diff --git a/mypy/messages.py b/mypy/messages.py
index f6cadf026788..ccfc70a8051f 100644
--- a/mypy/messages.py
+++ b/mypy/messages.py
@@ -612,13 +612,10 @@ def unexpected_keyword_argument(self, callee: CallableType, name: str,
         if callee.name:
             msg += ' for {}'.format(callee.name)
         self.fail(msg, context)
-        if callee.definition:
-            fullname = callee.definition.fullname()
-            if fullname is not None and '.' in fullname:
-                module_name = fullname.rsplit('.', 1)[0]
-                path = self.modules[module_name].path
-                self.note('{} defined here'.format(callee.name), callee.definition,
-                          file=path, origin=context)
+        module = find_defining_module(self.modules, callee)
+        if module:
+            self.note('{} defined here'.format(callee.name), callee.definition,
+                      file=module.path, origin=context)
 
     def duplicate_argument_value(self, callee: CallableType, index: int,
                                  context: Context) -> None:
@@ -946,6 +943,21 @@ def callable_name(type: CallableType) -> str:
         return 'function'
 
 
+def find_defining_module(modules: Dict[str, MypyFile], typ: CallableType) -> MypyFile:
+    if not typ.definition:
+        return None
+    fullname = typ.definition.fullname()
+    if fullname is not None and '.' in fullname:
+        for i in range(fullname.count('.')):
+            module_name = fullname.rsplit('.', i + 1)[0]
+            try:
+                return modules[module_name]
+            except KeyError:
+                pass
+        assert False, "Couldn't determine module from CallableType"
+    return None
+
+
 def temp_message_builder() -> MessageBuilder:
     """Return a message builder usable for throwaway errors (which may not format properly)."""
     return MessageBuilder(Errors(), {})
diff --git a/mypy/semanal.py b/mypy/semanal.py
index 95a7bf6e3630..3bde5cadf21c 100644
--- a/mypy/semanal.py
+++ b/mypy/semanal.py
@@ -328,6 +328,8 @@ def visit_func_def(self, defn: FuncDef) -> None:
             self.function_stack.append(defn)
             # First phase of analysis for function.
             self.errors.push_function(defn.name())
+            if not defn._fullname:
+                defn._fullname = self.qualified_name(defn.name())
             if defn.type:
                 assert isinstance(defn.type, CallableType)
                 self.update_function_type_variables(defn.type, defn)
diff --git a/test-data/unit/check-functions.test b/test-data/unit/check-functions.test
index c978c0e83353..1688d61b8c22 100644
--- a/test-data/unit/check-functions.test
+++ b/test-data/unit/check-functions.test
@@ -1932,7 +1932,7 @@ main:3: note: "f" defined here
 
 [case testMagicMethodPositionalOnlyArg]
 class A(object):
-    def __eq__(self, other) -> bool: return True # We are all equal.
+    def __eq__(self, other) -> bool: return True # We are all equal.  # N: "__eq__" of "A" defined here
 
 a = A()
 a.__eq__(a)
@@ -1944,7 +1944,7 @@ a.__eq__(other=a) # E: Unexpected keyword argument "other" for "__eq__" of "A"
 
 
 class A(object):
-    def __eq__(self, other) -> bool: return True # We are all equal.
+    def __eq__(self, other) -> bool: return True # We are all equal.  # N: "__eq__" of "A" defined here
 
 a = A()
 a.__eq__(a)
diff --git a/test-data/unit/check-kwargs.test b/test-data/unit/check-kwargs.test
index 61c0a5a0d5d7..de229c76e631 100644
--- a/test-data/unit/check-kwargs.test
+++ b/test-data/unit/check-kwargs.test
@@ -320,7 +320,7 @@ f(y=0) # E: Unexpected keyword argument "y" for "f"
 [case testKeywordArgumentAndCommentSignature2]
 import typing
 class A:
-    def f(self, x): # type: (int) -> str
+    def f(self, x): # type: (int) -> str  # N: "f" of "A" defined here
         pass
 A().f(x='') # E: Argument 1 to "f" of "A" has incompatible type "str"; expected "int"
 A().f(x=0)
@@ -359,3 +359,18 @@ f(**c) # E: Keywords must be strings
 def f(**k): pass
 f(*(1, 2))  # E: Too many arguments for "f"
 [builtins fixtures/dict.pyi]
+
+[case testUnexpectedMethodKwargInNestedClass]
+class A:
+    class B:
+        def __init__(self) -> None:  # N: "B" defined here
+            pass
+A.B(x=1)  # E: Unexpected keyword argument "x" for "B"
+
+[case testUnexpectedMethodKwargFromOtherModule]
+import m
+m.A(x=1)  # E: Unexpected keyword argument "x" for "A"
+[file m.py]
+class A:
+    def __init__(self) -> None:  # N: "A" defined here
+        pass
diff --git a/test-data/unit/semanal-classes.test b/test-data/unit/semanal-classes.test
index bb79b4264106..96c6ffe32523 100644
--- a/test-data/unit/semanal-classes.test
+++ b/test-data/unit/semanal-classes.test
@@ -270,7 +270,7 @@ MypyFile:1(
         PassStmt:2()))
     AssignmentStmt:3(
       NameExpr(g* [m])
-      NameExpr(f [m]))))
+      NameExpr(f [__main__.A.f]))))
 
 [case testIfStatementInClassBody]
 class A: