diff --git a/docs/source/running_mypy.rst b/docs/source/running_mypy.rst
index 2e482b599a88..5c1f6bea96e1 100644
--- a/docs/source/running_mypy.rst
+++ b/docs/source/running_mypy.rst
@@ -131,60 +131,109 @@ Missing imports
 When you import a module, mypy may report that it is unable to
 follow the import.
 
-This could happen if the code is importing a non-existent module
-or if the code is importing a library that does not use type hints.
-Specifically, the library is neither declared to be a 
-:ref:`PEP 561 compliant package <installed-packages>` nor has registered
-any stubs on `typeshed <https://github.com/python/typeshed>`_, the
-repository of stubs for the standard library and popular 3rd party libraries.
-
 This can cause a lot of errors that look like the following::
 
     main.py:1: error: No library stub file for standard library module 'antigravity'
     main.py:2: error: No library stub file for module 'flask'
     main.py:3: error: Cannot find module named 'this_module_does_not_exist'
 
-If the module genuinely does not exist, you should of course fix the
-import statement. If the module is a module within your codebase that mypy
-is somehow unable to discover, we recommend reading the :ref:`finding-imports`
-section below to help you debug the issue.
-
-If the module is a library that does not use type hints, the easiest fix
-is to silence the error messages by adding a ``# type: ignore`` comment on
-each respective import statement.
-
-If you have many of these errors from a specific library, it may be more
-convenient to silence all of those errors at once using the
-:ref:`mypy config file <config-file>`. For example, suppose your codebase
-makes heavy use of an (untyped) library named `foobar`. You can silence all
-import errors associated with that library and that library alone by adding
-the following section to your config file::
-
-    [mypy-foobar]
-    ignore_missing_imports = True
-
-Note: this option is equivalent to adding a ``# type: ignore`` to every
-import of ``foobar`` in your codebase. For more information, see the
-documentation about configuring
-:ref:`import discovery <config-file-import-discovery-per-module>` in config files.
-
-If you would like to silence *all* missing import errors in your codebase,
-you can do so by using the ``--ignore-missing-imports`` flag. We recommend
-using this flag only as a last resort: it's equivalent to adding a
-``# type: ignore`` to all unresolved imports in your codebase.
-
-A more involved solution would be to reverse-engineer how the library
-works, create type hints for the library, and point mypy at those
-type hints either by passing in in via the command line or by adding
-the location of your custom stubs to either the ``MYPYPATH`` environment
-variable or the ``mypy_path`` 
-:ref:`config file option <config-file-import-discovery-global>`.
-
-If you want to share your work, you can try contributing your stubs back
-to the library -- see our documentation on creating
-:ref:`PEP 561 compliant packages <installed-packages>`.
-
-
+There are several different things you can try doing, depending on the exact
+nature of the module.
+
+If the module is a part of your own codebase, try:
+
+1.  Making sure your import does not contain a typo.
+2.  Reading the :ref:`finding-imports` section below to make sure you
+    understand how exactly mypy searches for and finds modules and modify
+    how you're invoking mypy accordingly.
+3.  Adding the directory containing that module to either the ``MYPYPATH``
+    environment variable or the ``mypy_path``
+    :ref:`config file option <config-file-import-discovery-global>`.
+
+    Note: if the module you are trying to import is actually a *submodule* of
+    some package, you should add the directory containing the *entire* package
+    to ``MYPYPATH``. For example, suppose you are trying to add the module
+    ``foo.bar.baz``, which is located at ``~/foo-project/src/foo/bar/baz.py``.
+    In this case, you should add ``~/foo-project/src`` to ``MYPYPATH``.
+
+If the module is a third party library, you must make sure that there are
+type hints available for that library. Mypy by default will not attempt to
+infer the types of any 3rd party libraries you may have installed
+unless they either have declared themselves to be
+:ref:`PEP 561 compliant stub package <installed-packages>` or have registered
+themselves on `typeshed <https://github.com/python/typeshed>`_,
+the repository of types for the standard library and some 3rd party libraries.
+
+If you are getting an import-related error, this means the library you
+are trying to use has done neither of these things. In that case, you can try:
+
+1.  Searching to see if there is a :ref:`PEP 561 compliant stub package <installed-packages>`.
+    corresponding to your third party library. Stub packages let you install
+    type hints independently from the library itself.
+
+2.  :ref:`Writing your own stub files <stub-files>` containing type hints for
+    the library. You can point mypy at your type hints either by passing
+    them in via the command line, by adding the location to the 
+    `MYPYPATH` environment variable, or by using the  ``mypy_path`` 
+    :ref:`config file option <config-file-import-discovery-global>`. 
+
+    Note that if you decide to write your own stub files, they don't need
+    to be complete! A good strategy is to add stubs for just the parts
+    of the library you need and iterate on them over time.
+
+    If you want to share your work, you can try contributing your stubs back
+    to the library -- see our documentation on creating
+    :ref:`PEP 561 compliant packages <installed-packages>`.
+
+If the module is a third party library, but you cannot find any existing
+type hints nor have to time to write your own, you can *silence* the errors:
+
+1.  To silence a *single* missing import error, add a `# type: ignore` at the end of the
+    line containing the import.
+
+2.  To silence *all* missing import imports errors from a single library, add
+    a section to your :ref:`mypy config file <config-file>` for that library setting
+    ``ignore_missing_imports`` to True. For example, suppose your codebase
+    makes heavy use of an (untyped) library named ``foobar``. You can silence
+    all import errors associated with that library and that library alone by
+    adding the following section to your config file::
+
+        [mypy-foobar]
+        ignore_missing_imports = True
+
+    Note: this option is equivalent to adding a ``# type: ignore`` to every
+    import of ``foobar`` in your codebase. For more information, see the
+    documentation about configuring
+    :ref:`import discovery <config-file-import-discovery-per-module>` in config files.
+
+3.  To silence *all* missing import errors for *all* libraries in your codebase,
+    invoke mypy with the ``--ignore-missing-imports`` command line flag or set
+    the ``ignore_missing_imports``
+    :ref:`config file option <config-file-import-discovery-per-module` to True
+    in the *global* section of your mypy config file::
+
+        [mypy]
+        ignore_missing_imports = True
+
+    We recommend using this approach only as a last resort: it's equivalent
+    to adding a ``# type: ignore`` to all unresolved imports in your codebase.
+
+If the module is a part of the standard library, try:
+
+1.  Updating mypy and re-running it. It's possible type hints for that corner
+    of the standard library were added in a later version of mypy.
+
+2.  Filing a bug report on `typeshed <https://github.com/python/typeshed>`_,
+    the repository of type hints for the standard library that comes bundled
+    with mypy. You can expedite this process by also submitting a pull request
+    fixing the bug.
+
+    Changes to typeshed will come bundled with mypy the next time it's released.
+    In the meantime, you can add a ``# type: ignore`` to silence any relevant
+    errors. After upgrading, we recommend running mypy using the
+    ``--warn-unused-ignores`` flag to help you find any ``# type: ignore``
+    annotations you no longer need.
+     
 .. _follow-imports:
 
 Following imports
diff --git a/mypy/build.py b/mypy/build.py
index 9c18f5c93bf9..0b620e99e94a 100644
--- a/mypy/build.py
+++ b/mypy/build.py
@@ -2131,10 +2131,9 @@ def module_not_found(manager: BuildManager, line: int, caller_state: State,
         errors.report(line, 0, "No library stub file for module '{}'".format(target))
         errors.report(line, 0, stub_msg, severity='note', only_once=True)
     else:
+        note = "See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports"
         errors.report(line, 0, "Cannot find module named '{}'".format(target))
-        errors.report(line, 0, '(Perhaps setting MYPYPATH '
-                      'or using the "--ignore-missing-imports" flag would help)',
-                      severity='note', only_once=True)
+        errors.report(line, 0, note, severity='note', only_once=True)
     errors.set_import_context(save_import_context)
 
 
diff --git a/mypy/test/testpep561.py b/mypy/test/testpep561.py
index f72107e0ab86..897bdd4919e1 100644
--- a/mypy/test/testpep561.py
+++ b/mypy/test/testpep561.py
@@ -59,8 +59,8 @@ class SimpleMsg(Enum):
 class NamespaceMsg(Enum):
     cfm_beta = ("{tempfile}:4: error: Cannot find module named "
                 "'typedpkg_ns.ns.dne'")
-    help_note = ('{tempfile}:4: note: (Perhaps setting MYPYPATH or using the '
-                 '"--ignore-missing-imports" flag would help)')
+    help_note = ('{tempfile}:4: note: See https://mypy.readthedocs.io/en/latest/'
+                 'running_mypy.html#missing-imports')
     bool_str = ('{tempfile}:10: error: Argument 1 has incompatible type '
                 '"bool"; expected "str"')
     int_bool = ('{tempfile}:11: error: Argument 1 has incompatible type '
diff --git a/test-data/unit/check-flags.test b/test-data/unit/check-flags.test
index 4c611bc42262..9b4af4f08e41 100644
--- a/test-data/unit/check-flags.test
+++ b/test-data/unit/check-flags.test
@@ -439,7 +439,7 @@ main:2: note: (Using --follow-imports=error, module not passed on command line)
 from mod import x
 [out]
 main:1: error: Cannot find module named 'mod'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testIgnoreMissingImportsTrue]
 # flags: --ignore-missing-imports
@@ -594,7 +594,7 @@ def f(x: MyType) -> None:
     pass
 [out]
 main:2: error: Cannot find module named 'missing'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: Argument 1 to "f" becomes "Any" due to an unfollowed import
 
 [case testDisallowImplicitAnyVariableDefinition]
diff --git a/test-data/unit/check-incremental.test b/test-data/unit/check-incremental.test
index 593379f49197..b30466ffdf28 100644
--- a/test-data/unit/check-incremental.test
+++ b/test-data/unit/check-incremental.test
@@ -2082,7 +2082,7 @@ x = 1
 [stale]
 [out2]
 tmp/n.py:1: error: Cannot find module named 'm'
-tmp/n.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/n.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testDeleteFileWithinCycle]
 import a
@@ -2748,10 +2748,10 @@ a.f() # Comment change
 [stale3 b]
 [out2]
 tmp/b.py:1: error: Cannot find module named 'a'
-tmp/b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 [out3]
 tmp/b.py:1: error: Cannot find module named 'a'
-tmp/b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 [out4]
 
 [case testQuickAndDirtyRenameModule]
@@ -4063,7 +4063,7 @@ import a
 
 [out2]
 main:2: error: Cannot find module named 'a'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testIncrementalInheritanceAddAnnotation]
 # flags: --strict-optional
@@ -4206,7 +4206,7 @@ def f(x: int) -> None: pass
 [out]
 [out2]
 main:1: error: Cannot find module named 'p.q'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 [out3]
 main:2: error: Too few arguments for "f"
 
@@ -4808,10 +4808,10 @@ def __getattr__(attr: str) -> Any: ...
 [builtins fixtures/module.pyi]
 [out]
 tmp/c.py:1: error: Cannot find module named 'a.b.c'
-tmp/c.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/c.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 [out2]
 tmp/c.py:1: error: Cannot find module named 'a.b.c'
-tmp/c.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/c.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testAddedMissingStubs]
 # flags: --ignore-missing-imports
diff --git a/test-data/unit/check-modules.test b/test-data/unit/check-modules.test
index 2e1ba918df82..8b53930eda41 100644
--- a/test-data/unit/check-modules.test
+++ b/test-data/unit/check-modules.test
@@ -201,7 +201,7 @@ import nonexistent
 None + ''
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 
 [case testTypeCheckWithUnknownModule2]
@@ -213,7 +213,7 @@ m.x = ''
 x = 1
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 main:4: error: Incompatible types in assignment (expression has type "str", variable has type "int")
 
@@ -226,7 +226,7 @@ m.x = ''
 x = 1
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 main:4: error: Incompatible types in assignment (expression has type "str", variable has type "int")
 
@@ -235,7 +235,7 @@ import nonexistent, another
 None + ''
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'another'
 main:2: error: Unsupported left operand type for + ("None")
 
@@ -244,7 +244,7 @@ import nonexistent as x
 None + ''
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 
 [case testTypeCheckWithUnknownModuleUsingFromImport]
@@ -252,7 +252,7 @@ from nonexistent import x
 None + ''
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 
 [case testTypeCheckWithUnknownModuleUsingImportStar]
@@ -260,7 +260,7 @@ from nonexistent import *
 None + ''
 [out]
 main:1: error: Cannot find module named 'nonexistent'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Unsupported left operand type for + ("None")
 
 [case testAccessingUnknownModule]
@@ -269,7 +269,7 @@ xyz.foo()
 xyz()
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testAccessingUnknownModule2]
 import xyz, bar
@@ -277,7 +277,7 @@ xyz.foo()
 bar()
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'bar'
 
 [case testAccessingUnknownModule3]
@@ -286,7 +286,7 @@ xyz.foo()
 z()
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Name 'xyz' is not defined
 
 [case testAccessingNameImportedFromUnknownModule]
@@ -295,14 +295,14 @@ y.foo()
 z()
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testAccessingNameImportedFromUnknownModule2]
 from xyz import *
 y
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Name 'y' is not defined
 
 [case testAccessingNameImportedFromUnknownModule3]
@@ -311,7 +311,7 @@ y
 z
 [out]
 main:1: error: Cannot find module named 'xyz'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Name 'y' is not defined
 
 [case testUnknownModuleRedefinition]
@@ -319,7 +319,7 @@ import xab
 def xab(): pass
 [out]
 main:1: error: Cannot find module named 'xab'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testAccessingUnknownModuleFromOtherModule]
 import x
@@ -330,7 +330,7 @@ import nonexistent
 [builtins fixtures/module.pyi]
 [out]
 tmp/x.py:1: error: Cannot find module named 'nonexistent'
-tmp/x.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/x.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:3: error: Module has no attribute "z"
 
 [case testUnknownModuleImportedWithinFunction]
@@ -340,7 +340,7 @@ def foobar(): pass
 foobar('')
 [out]
 main:2: error: Cannot find module named 'foobar'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: Too many arguments for "foobar"
 
 [case testUnknownModuleImportedWithinFunction2]
@@ -350,7 +350,7 @@ def x(): pass
 x('')
 [out]
 main:2: error: Cannot find module named 'foobar'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: Too many arguments for "x"
 
 [case testRelativeImports]
@@ -2091,7 +2091,7 @@ import c
 -- TODO: it would be better for this to be in the other order
 tmp/b.py:1: error: Cannot find module named 'c'
 main:1: error: Cannot find module named 'c'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testIndirectFromImportWithinCycle1]
 import a
@@ -2225,7 +2225,7 @@ def __getattr__(attr: str) -> Any: ...
 [builtins fixtures/module.pyi]
 [out]
 main:1: error: Cannot find module named 'a.b'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testModuleGetattrInit4]
 import a.b.c
@@ -2267,7 +2267,7 @@ def __getattr__(attr: str) -> int: ...
 [builtins fixtures/module.pyi]
 [out]
 main:1: error: Cannot find module named 'a.b'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testModuleGetattrInit8]
 import a.b.c.d
@@ -2281,7 +2281,7 @@ def __getattr__(attr: str) -> Any: ...
 [builtins fixtures/module.pyi]
 [out]
 main:1: error: Cannot find module named 'a.b.c.d'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'a.b.c'
 
 [case testModuleGetattrInit8a]
@@ -2295,7 +2295,7 @@ def __getattr__(attr: str) -> Any: ...
 [builtins fixtures/module.pyi]
 [out]
 main:1: error: Cannot find module named 'a.b.c'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testModuleGetattrInit10]
 # flags: --config-file tmp/mypy.ini
@@ -2315,7 +2315,7 @@ ignore_missing_imports = True
 [builtins fixtures/module.pyi]
 [out]
 main:3: error: Cannot find module named 'a.b.d'
-main:3: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:3: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testIndirectFromImportWithinCycleUsedAsBaseClass-skip]
 -- TODO: Fails because of missing ImportedName handling in mypy.typeanal
@@ -2542,7 +2542,7 @@ from foo.bar import x
 x = 0
 [out]
 main:1: error: Cannot find module named 'foo.bar'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testNamespacePackage]
 # flags: --namespace-packages
diff --git a/test-data/unit/check-python2.test b/test-data/unit/check-python2.test
index e864da951916..12304fe86eda 100644
--- a/test-data/unit/check-python2.test
+++ b/test-data/unit/check-python2.test
@@ -156,7 +156,7 @@ import asyncio
 import Bastion
 [out]
 main:1: error: Cannot find module named 'asyncio'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: No library stub file for standard library module 'Bastion'
 main:2: note: (Stub files are from https://github.com/python/typeshed)
 
diff --git a/test-data/unit/check-semanal-error.test b/test-data/unit/check-semanal-error.test
index 1869bbe8e366..112a60d92b8d 100644
--- a/test-data/unit/check-semanal-error.test
+++ b/test-data/unit/check-semanal-error.test
@@ -19,7 +19,7 @@ m.x = m.y
 1() # E
 [out]
 main:1: error: Cannot find module named 'm'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: "int" not callable
 
 [case testMissingModuleImport2]
@@ -29,7 +29,7 @@ x.a = x.b
 1() # E
 [out]
 main:1: error: Cannot find module named 'm'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: "int" not callable
 
 [case testMissingModuleImport3]
@@ -38,7 +38,7 @@ x # E
 1() # E
 [out]
 main:1: error: Cannot find module named 'm'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Name 'x' is not defined
 main:3: error: "int" not callable
 
diff --git a/test-data/unit/check-unreachable-code.test b/test-data/unit/check-unreachable-code.test
index 144cf926001a..11683c04c560 100644
--- a/test-data/unit/check-unreachable-code.test
+++ b/test-data/unit/check-unreachable-code.test
@@ -78,7 +78,7 @@ else:
 [builtins fixtures/bool.pyi]
 [out]
 main:6: error: Cannot find module named 'pow123'
-main:6: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:6: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testMypyConditional]
 import typing
@@ -97,7 +97,7 @@ else:
     import xyz753
 [out]
 main:3: error: Cannot find module named 'pow123'
-main:3: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:3: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testTypeCheckingConditionalFromImport]
 from typing import TYPE_CHECKING
@@ -107,7 +107,7 @@ else:
     import xyz753
 [out]
 main:3: error: Cannot find module named 'pow123'
-main:3: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:3: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testNegatedTypeCheckingConditional]
 import typing
@@ -118,7 +118,7 @@ else:
 [builtins fixtures/bool.pyi]
 [out]
 main:5: error: Cannot find module named 'xyz753'
-main:5: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:5: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testUndefinedTypeCheckingConditional]
 if not TYPE_CHECKING: # E
@@ -129,7 +129,7 @@ else:
 [out]
 main:1: error: Name 'TYPE_CHECKING' is not defined
 main:4: error: Cannot find module named 'xyz753'
-main:4: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:4: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testConditionalClassDefPY3]
 def f(): pass
@@ -443,7 +443,7 @@ class A:
             # TODO: This is inconsistent with how top-level functions work
             #     (https://github.com/python/mypy/issues/4324)
             import b as a # E: Cannot find module named 'b' \
-            # N: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+            # N: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
         else:
             import a
         a.x
diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
index 83f6fe35f1c5..37707bbdc895 100644
--- a/test-data/unit/cmdline.test
+++ b/test-data/unit/cmdline.test
@@ -295,7 +295,7 @@ baz(bar(foo(42)))
 baz(bar(foo('oof')))
 [out]
 file.py:1: error: Cannot find module named 'no_stubs'
-file.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+file.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 file.py:6: error: Argument 1 to "foo" has incompatible type "str"; expected "int"
 
 [case testIgnoreErrorsConfig]
@@ -440,7 +440,7 @@ reveal_type(missing.x)  # Expect Any
 ignore_missing_imports = False
 [out]
 main.py:1: error: Cannot find module named 'missing'
-main.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main.py:2: error: Revealed type is 'Any'
 
 [case testConfigSilentMissingImportsOn]
@@ -487,7 +487,7 @@ import a.b
 whatever
 [out]
 main.py:1: error: Cannot find module named 'a.b'
-main.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main.py:1: error: Cannot find module named 'a'
 
 [case testPythonVersionTooOld10]
diff --git a/test-data/unit/fine-grained-blockers.test b/test-data/unit/fine-grained-blockers.test
index 5adcb499529f..43c59a20f48b 100644
--- a/test-data/unit/fine-grained-blockers.test
+++ b/test-data/unit/fine-grained-blockers.test
@@ -112,7 +112,7 @@ x x
 def f() -> None: pass
 [out]
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 a.py:1: error: invalid syntax
 ==
@@ -255,7 +255,7 @@ x x
 a.py:1: error: invalid syntax
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 b.py:1: error: Cannot find module named 'a'
 
 [case testDeleteFileWithBlockingError-only_when_cache]
@@ -276,7 +276,7 @@ x x
 a.py:1: error: invalid syntax
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'a'
 
 [case testModifyFileWhileBlockingErrorElsewhere]
@@ -349,7 +349,7 @@ class A: pass
 [out]
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:4: error: "A" has no attribute "f"
 
@@ -367,7 +367,7 @@ class A:
 [out]
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:1: error: Module 'a' has no attribute 'A'
 
diff --git a/test-data/unit/fine-grained-modules.test b/test-data/unit/fine-grained-modules.test
index 2e1bc5de182b..a4d5372de9b1 100644
--- a/test-data/unit/fine-grained-modules.test
+++ b/test-data/unit/fine-grained-modules.test
@@ -53,7 +53,7 @@ def f() -> None: pass
 [out]
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 
 [case testAddFileFixesAndGeneratesError1]
@@ -69,10 +69,10 @@ def f() -> None: pass
 [out]
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 b.py:2: error: Too many arguments for "f"
 
@@ -89,10 +89,10 @@ def f() -> None: pass
 [out]
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 b.py:2: error: Too many arguments for "f"
 
@@ -119,10 +119,10 @@ f(1)
 [out]
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 b.py:1: error: Cannot find module named 'a'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testAddFilePreservesError2]
 import b
@@ -162,7 +162,7 @@ import a
 [out]
 ==
 b.py:2: error: Cannot find module named 'a'
-b.py:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testImportLineNumber2]
 import b
@@ -175,11 +175,11 @@ from c import f
 [out]
 ==
 b.py:2: error: Cannot find module named 'a'
-b.py:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 b.py:3: error: Cannot find module named 'c'
 ==
 b.py:2: error: Cannot find module named 'a'
-b.py:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 b.py:3: error: Cannot find module named 'c'
 
 [case testAddPackage1]
@@ -190,7 +190,7 @@ p.a.f(1)
 def f(x: str) -> None: pass
 [out]
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 ==
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
@@ -204,7 +204,7 @@ from p.a import f
 def f(x: str) -> None: pass
 [out]
 main:1: error: Cannot find module named 'p'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 
@@ -216,11 +216,11 @@ p.a.f(1)
 def f(x: str) -> None: pass
 [out]
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 [builtins fixtures/module.pyi]
@@ -233,11 +233,11 @@ def f(x: str) -> None: pass
 [file p/__init__.py.3]
 [out]
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 ==
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
@@ -267,11 +267,11 @@ def f(x: str) -> None: pass
 [file p/__init__.py.3]
 [out]
 main:4: error: Cannot find module named 'p.a'
-main:4: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:4: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: Cannot find module named 'p'
 ==
 main:4: error: Cannot find module named 'p.a'
-main:4: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:4: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:4: error: Cannot find module named 'p'
 ==
 main:5: error: Argument 1 to "f" has incompatible type "int"; expected "str"
@@ -302,7 +302,7 @@ def f(x: str) -> None: pass
 [file p/__init__.py.2]
 [out]
 x.py:1: error: Cannot find module named 'p.a'
-x.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+x.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 x.py:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 
@@ -375,7 +375,7 @@ def f(x: int) -> None: pass
 [out]
 ==
 a.py:1: error: Cannot find module named 'b'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 a.py:4: error: Too few arguments for "f"
 
@@ -389,7 +389,7 @@ def f() -> None: pass
 [out]
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 
 [case testDeletionOfSubmoduleTriggersImportFrom1-only_when_nocache]
@@ -405,7 +405,7 @@ from p import q
 main:1: error: Module 'p' has no attribute 'q'
 -- TODO: The following messages are different compared to non-incremental mode
 main:1: error: Cannot find module named 'p.q'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 
 -- TODO: Fix this bug. It is a real bug that was been papered over
@@ -421,7 +421,7 @@ from p import q
 [out]
 ==
 main:1: error: Cannot find module named 'p.q'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 
 [case testDeletionOfSubmoduleTriggersImportFrom2]
@@ -436,7 +436,7 @@ def f(x: int) -> None: pass
 [out]
 ==
 main:1: error: Cannot find module named 'p.q'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:2: error: Too few arguments for "f"
 
@@ -451,7 +451,7 @@ def f(x: int) -> None: pass
 [out]
 ==
 main:1: error: Cannot find module named 'p.q'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 
 [case testDeleteSubpackageWithNontrivialParent1]
@@ -482,7 +482,7 @@ def f() -> str:
 a.py:2: error: Incompatible return value type (got "int", expected "str")
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testDeleteModuleWithErrorInsidePackage]
 import a.b
@@ -497,7 +497,7 @@ def f() -> str:
 a/b.py:2: error: Incompatible return value type (got "str", expected "int")
 ==
 main:1: error: Cannot find module named 'a.b'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testModifyTwoFilesNoError1]
 import a
@@ -636,7 +636,7 @@ def g() -> None: pass
 b.f()
 [out]
 a.py:1: error: Cannot find module named 'b'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 a.py:2: error: Cannot find module named 'c'
 ==
 
@@ -657,7 +657,7 @@ def g() -> None: pass
 b.f(1)
 [out]
 a.py:1: error: Cannot find module named 'b'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 a.py:2: error: Cannot find module named 'c'
 ==
 c.py:3: error: Too many arguments for "f"
@@ -674,7 +674,7 @@ def f() -> None: pass
 def g() -> None: pass
 [out]
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Cannot find module named 'b'
 ==
 main:3: error: Too many arguments for "f"
@@ -694,7 +694,7 @@ def g() -> None: pass
 [out]
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Cannot find module named 'b'
 
 [case testDeleteTwoFilesNoErrors]
@@ -735,7 +735,7 @@ b.py:3: error: Too many arguments for "f"
 a.py:3: error: Too many arguments for "g"
 ==
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Cannot find module named 'b'
 
 [case testAddFileWhichImportsLibModule]
@@ -746,7 +746,7 @@ import sys
 x = sys.platform
 [out]
 main:1: error: Cannot find module named 'a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:2: error: Incompatible types in assignment (expression has type "int", variable has type "str")
 
@@ -760,7 +760,7 @@ x = broken.x
 z
 [out]
 main:2: error: Cannot find module named 'a'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 a.py:3: error: Name 'z' is not defined
 <ROOT>/test-data/unit/lib-stub/broken.pyi:2: error: Name 'y' is not defined
@@ -825,7 +825,7 @@ def g() -> None: pass
 a.py:2: error: Too many arguments for "g"
 ==
 a.py:1: error: Cannot find module named 'm.x'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testDeletePackage1]
 import p.a
@@ -840,7 +840,7 @@ def f(x: str) -> None: pass
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 
 [case testDeletePackage2]
@@ -856,7 +856,7 @@ def f(x: str) -> None: pass
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 main:1: error: Cannot find module named 'p'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testDeletePackage3]
 import p.a
@@ -871,10 +871,10 @@ def f(x: str) -> None: pass
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 
 [case testDeletePackage4]
@@ -889,11 +889,11 @@ def f(x: str) -> None: pass
 main:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 ==
 main:1: error: Cannot find module named 'p.a'
-main:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:1: error: Cannot find module named 'p'
 
 [case testDeletePackage5]
@@ -912,11 +912,11 @@ def f(x: str) -> None: pass
 main:6: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 main:5: error: Cannot find module named 'p.a'
-main:5: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:5: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:5: error: Cannot find module named 'p'
 ==
 main:5: error: Cannot find module named 'p.a'
-main:5: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:5: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:5: error: Cannot find module named 'p'
 
 
@@ -938,7 +938,7 @@ f(12)
 p/b.py:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 ==
 p/b.py:1: error: Cannot find module named 'p.a'
-p/b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+p/b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 p/b.py:2: error: Argument 1 to "f" has incompatible type "int"; expected "str"
 
@@ -1411,7 +1411,7 @@ def f() -> None: pass
 [out]
 ==
 a.py:1: error: Cannot find module named 'b'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 
 [case testRefreshImportIfMypyElse1]
@@ -1806,7 +1806,7 @@ x = 2
 ==
 ==
 a.py:2: error: Cannot find module named 'b'
-a.py:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testErrorButDontIgnore1]
 # cmd: mypy a.py c.py
@@ -1881,7 +1881,7 @@ x = 1
 p/b.py: note: Ancestor package 'p' ignored
 p/b.py: note: (Using --follow-imports=error, submodule passed on command line)
 p/b.py:1: error: Cannot find module named 'z'
-p/b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+p/b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testTurnPackageToModule]
 [file a.py]
diff --git a/test-data/unit/fine-grained.test b/test-data/unit/fine-grained.test
index 9556535871f8..cee3fa709d47 100644
--- a/test-data/unit/fine-grained.test
+++ b/test-data/unit/fine-grained.test
@@ -451,7 +451,7 @@ x = 3
 ==
 ==
 a.py:1: error: Cannot find module named 'b'
-a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testIgnoreWorksWithMissingImports]
 import a
@@ -485,7 +485,7 @@ from xyz import x  # type: ignore
 x = str()
 [out]
 b.py:1: error: Cannot find module named 'xyz'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 ==
 a.py:2: error: Incompatible types in assignment (expression has type "str", variable has type "int")
@@ -504,7 +504,7 @@ x = str()
 [out]
 ==
 b.py:1: error: Cannot find module named 'xyz'
-b.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+b.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 a.py:2: error: Incompatible types in assignment (expression has type "str", variable has type "int")
 
@@ -1753,7 +1753,7 @@ def f() -> Iterator[None]:
 main:2: error: Revealed type is 'contextlib.GeneratorContextManager[None]'
 ==
 a.py:3: error: Cannot find module named 'b'
-a.py:3: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:3: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Revealed type is 'contextlib.GeneratorContextManager[None]'
 ==
 main:2: error: Revealed type is 'contextlib.GeneratorContextManager[None]'
@@ -1800,7 +1800,7 @@ def g() -> None:
 a.py:11: error: Too many arguments for "h"
 ==
 a.py:10: error: Cannot find module named 'b'
-a.py:10: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:10: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 a.py:11: error: Too many arguments for "h"
 ==
@@ -1834,7 +1834,7 @@ def f(x: List[int]) -> Iterator[None]:
 [out]
 ==
 a.py:3: error: Cannot find module named 'b'
-a.py:3: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+a.py:3: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 ==
 ==
 
@@ -2453,7 +2453,7 @@ def g() -> None: pass
 [out]
 ==
 main:2: error: Cannot find module named 'm'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:7: error: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader
 main:9: error: Cannot find module named 'n'
 
@@ -2482,7 +2482,7 @@ def g() -> None: pass
 [out]
 ==
 main:2: error: Cannot find module named 'm'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:12: error: Overloaded function signature 2 will never be matched: signature 1's parameter type(s) are the same or broader
 main:14: error: Cannot find module named 'n'
 
diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index 54da1e212f0f..83c4570897e4 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -1211,7 +1211,7 @@ bar: Type[C]
 bar * 4 + bar + 3  # should not produce more errors
 [out]
 _testMetaclassOpAccessAny.py:2: error: Cannot find module named 'nonexistent'
-_testMetaclassOpAccessAny.py:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+_testMetaclassOpAccessAny.py:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testEnumIterationAndPreciseElementType]
 # Regression test for #2305
diff --git a/test-data/unit/semanal-errors.test b/test-data/unit/semanal-errors.test
index f3588e36148b..342d0fa749ec 100644
--- a/test-data/unit/semanal-errors.test
+++ b/test-data/unit/semanal-errors.test
@@ -198,21 +198,21 @@ import typing
 import m
 [out]
 main:2: error: Cannot find module named 'm'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testMissingModule2]
 import typing
 from m import x
 [out]
 main:2: error: Cannot find module named 'm'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testMissingModule3]
 import typing
 from m import *
 [out]
 main:2: error: Cannot find module named 'm'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testMissingModuleRelativeImport]
 import typing
@@ -221,7 +221,7 @@ import m
 from .x import y
 [out]
 tmp/m/__init__.py:1: error: Cannot find module named 'm.x'
-tmp/m/__init__.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/m/__init__.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testMissingModuleRelativeImport2]
 import typing
@@ -231,7 +231,7 @@ import m.a
 from .x import y
 [out]
 tmp/m/a.py:1: error: Cannot find module named 'm.x'
-tmp/m/a.py:1: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+tmp/m/a.py:1: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 
 [case testModuleNotImported]
 import typing
@@ -280,7 +280,7 @@ import typing
 import m.n
 [out]
 main:2: error: Cannot find module named 'm.n'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Cannot find module named 'm'
 
 [case testMissingPackage2]
@@ -289,7 +289,7 @@ from m.n import x
 from a.b import *
 [out]
 main:2: error: Cannot find module named 'm.n'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:3: error: Cannot find module named 'a.b'
 
 [case testErrorInImportedModule]
@@ -319,7 +319,7 @@ m.n.x
 x = 1
 [out]
 main:2: error: Cannot find module named 'm.n'
-main:2: note: (Perhaps setting MYPYPATH or using the "--ignore-missing-imports" flag would help)
+main:2: note: See https://mypy.readthedocs.io/en/latest/running_mypy.html#missing-imports
 main:2: error: Cannot find module named 'm'
 
 [case testBreakOutsideLoop]