diff --git a/mypy/myunit/__init__.py b/mypy/myunit/__init__.py
index 6ffa3293929f..fa4000266849 100644
--- a/mypy/myunit/__init__.py
+++ b/mypy/myunit/__init__.py
@@ -1,371 +1 @@
-import importlib
-import os
-import sys
-import re
-import tempfile
-import time
-import traceback
-
-from typing import List, Tuple, Any, Callable, Union, cast
-
-
-# TODO remove global state
-is_verbose = False
-is_quiet = False
-patterns = []  # type: List[str]
-times = []  # type: List[Tuple[float, str]]
-APPEND_TESTCASES = ''
-UPDATE_TESTCASES = False
-
-
-class AssertionFailure(Exception):
-    """Exception used to signal skipped test cases."""
-    def __init__(self, s: str = None) -> None:
-        if s:
-            super().__init__(s)
-        else:
-            super().__init__()
-
-
-class SkipTestCaseException(Exception): pass
-
-
-def assert_true(b: bool, msg: str = None) -> None:
-    if not b:
-        raise AssertionFailure(msg)
-
-
-def assert_false(b: bool, msg: str = None) -> None:
-    if b:
-        raise AssertionFailure(msg)
-
-
-def good_repr(obj: object) -> str:
-    if isinstance(obj, str):
-        if obj.count('\n') > 1:
-            bits = ["'''\\"]
-            for line in obj.split('\n'):
-                # force repr to use ' not ", then cut it off
-                bits.append(repr('"' + line)[2:-1])
-            bits[-1] += "'''"
-            return '\n'.join(bits)
-    return repr(obj)
-
-
-def assert_equal(a: object, b: object, fmt: str = '{} != {}') -> None:
-    if a != b:
-        raise AssertionFailure(fmt.format(good_repr(a), good_repr(b)))
-
-
-def assert_not_equal(a: object, b: object, fmt: str = '{} == {}') -> None:
-    if a == b:
-        raise AssertionFailure(fmt.format(good_repr(a), good_repr(b)))
-
-
-def assert_raises(typ: type, *rest: Any) -> None:
-    """Usage: assert_raises(exception class[, message], function[, args])
-
-    Call function with the given arguments and expect an exception of the given
-    type.
-
-    TODO use overloads for better type checking
-    """
-    # Parse arguments.
-    msg = None  # type: str
-    if isinstance(rest[0], str) or rest[0] is None:
-        msg = rest[0]
-        rest = rest[1:]
-    f = rest[0]
-    args = []  # type: List[Any]
-    if len(rest) > 1:
-        args = rest[1]
-        assert len(rest) <= 2
-
-    # Perform call and verify the exception.
-    try:
-        f(*args)
-    except Exception as e:
-        assert_type(typ, e)
-        if msg:
-            assert_equal(e.args[0], msg, 'Invalid message {}, expected {}')
-    else:
-        raise AssertionFailure('No exception raised')
-
-
-def assert_type(typ: type, value: object) -> None:
-    if type(value) != typ:
-        raise AssertionFailure('Invalid type {}, expected {}'.format(
-            typename(type(value)), typename(typ)))
-
-
-def fail() -> None:
-    raise AssertionFailure()
-
-
-class TestCase:
-    def __init__(self, name: str, suite: 'Suite' = None,
-                 func: Callable[[], None] = None) -> None:
-        self.func = func
-        self.name = name
-        self.suite = suite
-        self.old_cwd = None  # type: str
-        self.tmpdir = None  # type: tempfile.TemporaryDirectory
-
-    def run(self) -> None:
-        if self.func:
-            self.func()
-
-    def set_up(self) -> None:
-        self.old_cwd = os.getcwd()
-        self.tmpdir = tempfile.TemporaryDirectory(prefix='mypy-test-',
-                dir=os.path.abspath('tmp-test-dirs'))
-        os.chdir(self.tmpdir.name)
-        os.mkdir('tmp')
-        if self.suite:
-            self.suite.set_up()
-
-    def tear_down(self) -> None:
-        if self.suite:
-            self.suite.tear_down()
-        os.chdir(self.old_cwd)
-        self.tmpdir.cleanup()
-        self.old_cwd = None
-        self.tmpdir = None
-
-
-class Suite:
-    def __init__(self) -> None:
-        self.prefix = typename(type(self)) + '.'
-        # Each test case is either a TestCase object or (str, function).
-        self._test_cases = []  # type: List[Any]
-        self.init()
-
-    def set_up(self) -> None:
-        pass
-
-    def tear_down(self) -> None:
-        pass
-
-    def init(self) -> None:
-        for m in dir(self):
-            if m.startswith('test'):
-                t = getattr(self, m)
-                if isinstance(t, Suite):
-                    self.add_test((m + '.', t))
-                else:
-                    self.add_test(TestCase(m, self, getattr(self, m)))
-
-    def add_test(self, test: Union[TestCase,
-                                   Tuple[str, Callable[[], None]],
-                                   Tuple[str, 'Suite']]) -> None:
-        self._test_cases.append(test)
-
-    def cases(self) -> List[Any]:
-        return self._test_cases[:]
-
-    def skip(self) -> None:
-        raise SkipTestCaseException()
-
-
-def add_suites_from_module(suites: List[Suite], mod_name: str) -> None:
-    mod = importlib.import_module(mod_name)
-    got_suite = False
-    for suite in mod.__dict__.values():
-        if isinstance(suite, type) and issubclass(suite, Suite) and suite is not Suite:
-            got_suite = True
-            suites.append(cast(Callable[[], Suite], suite)())
-    if not got_suite:
-        # Sanity check in case e.g. it uses unittest instead of a myunit.
-        # The codecs tests do since they need to be python2-compatible.
-        sys.exit('Test module %s had no test!' % mod_name)
-
-
-class ListSuite(Suite):
-    def __init__(self, suites: List[Suite]) -> None:
-        for suite in suites:
-            mod_name = type(suite).__module__.replace('.', '_')
-            mod_name = mod_name.replace('mypy_', '')
-            mod_name = mod_name.replace('test_', '')
-            mod_name = mod_name.strip('_').replace('__', '_')
-            type_name = type(suite).__name__
-            name = 'test_%s_%s' % (mod_name, type_name)
-            setattr(self, name, suite)
-        super().__init__()
-
-
-def main(args: List[str] = None) -> None:
-    global patterns, is_verbose, is_quiet
-    global APPEND_TESTCASES, UPDATE_TESTCASES
-    if not args:
-        args = sys.argv[1:]
-    is_verbose = False
-    is_quiet = False
-    suites = []  # type: List[Suite]
-    patterns = []
-    i = 0
-    while i < len(args):
-        a = args[i]
-        if a == '-v':
-            is_verbose = True
-        elif a == '-q':
-            is_quiet = True
-        elif a == '-u':
-            APPEND_TESTCASES = '.new'
-            UPDATE_TESTCASES = True
-        elif a == '-i':
-            APPEND_TESTCASES = ''
-            UPDATE_TESTCASES = True
-        elif a == '-m':
-            i += 1
-            if i == len(args):
-                sys.exit('-m requires an argument')
-            add_suites_from_module(suites, args[i])
-        elif not a.startswith('-'):
-            patterns.append(a)
-        else:
-            sys.exit('Usage: python -m mypy.myunit [-v] [-q] [-u | -i]'
-                    + ' -m test.module [-m test.module ...] [filter ...]')
-        i += 1
-    if len(patterns) == 0:
-        patterns.append('*')
-    if not suites:
-        sys.exit('At least one -m argument is required')
-
-    t = ListSuite(suites)
-    num_total, num_fail, num_skip = run_test_recursive(t, 0, 0, 0, '', 0)
-
-    skip_msg = ''
-    if num_skip > 0:
-        skip_msg = ', {} skipped'.format(num_skip)
-
-    if num_fail == 0:
-        if not is_quiet:
-            print('%d test cases run%s, all passed.' % (num_total, skip_msg))
-            print('*** OK ***')
-    else:
-        sys.stderr.write('%d/%d test cases failed%s.\n' % (num_fail,
-                                                           num_total,
-                                                           skip_msg))
-        sys.stderr.write('*** FAILURE ***\n')
-        sys.exit(1)
-
-
-def run_test_recursive(test: Any, num_total: int, num_fail: int, num_skip: int,
-                       prefix: str, depth: int) -> Tuple[int, int, int]:
-    """The first argument may be TestCase, Suite or (str, Suite)."""
-    if isinstance(test, TestCase):
-        name = prefix + test.name
-        for pattern in patterns:
-            if match_pattern(name, pattern):
-                match = True
-                break
-        else:
-            match = False
-        if match:
-            is_fail, is_skip = run_single_test(name, test)
-            if is_fail: num_fail += 1
-            if is_skip: num_skip += 1
-            num_total += 1
-    else:
-        suite = None  # type: Suite
-        suite_prefix = ''
-        if isinstance(test, list) or isinstance(test, tuple):
-            suite = test[1]
-            suite_prefix = test[0]
-        else:
-            suite = test
-            suite_prefix = test.prefix
-
-        for stest in suite.cases():
-            new_prefix = prefix
-            if depth > 0:
-                new_prefix = prefix + suite_prefix
-            num_total, num_fail, num_skip = run_test_recursive(
-                stest, num_total, num_fail, num_skip, new_prefix, depth + 1)
-    return num_total, num_fail, num_skip
-
-
-def run_single_test(name: str, test: Any) -> Tuple[bool, bool]:
-    if is_verbose:
-        sys.stderr.write(name)
-        sys.stderr.flush()
-
-    time0 = time.time()
-    test.set_up()  # FIX: check exceptions
-    exc_traceback = None  # type: Any
-    try:
-        test.run()
-    except Exception:
-        exc_type, exc_value, exc_traceback = sys.exc_info()
-    test.tear_down()  # FIX: check exceptions
-    times.append((time.time() - time0, name))
-
-    if exc_traceback:
-        if isinstance(exc_value, SkipTestCaseException):
-            if is_verbose:
-                sys.stderr.write(' (skipped)\n')
-            return False, True
-        else:
-            handle_failure(name, exc_type, exc_value, exc_traceback)
-            return True, False
-    elif is_verbose:
-        sys.stderr.write('\n')
-
-    return False, False
-
-
-def handle_failure(name, exc_type, exc_value, exc_traceback) -> None:
-    # Report failed test case.
-    if is_verbose:
-        sys.stderr.write('\n\n')
-    msg = ''
-    if exc_value.args and exc_value.args[0]:
-        msg = ': ' + str(exc_value)
-    else:
-        msg = ''
-    sys.stderr.write('Traceback (most recent call last):\n')
-    tb = traceback.format_tb(exc_traceback)
-    tb = clean_traceback(tb)
-    for s in tb:
-        sys.stderr.write(s)
-    exception = typename(exc_type)
-    sys.stderr.write('{}{}\n\n'.format(exception, msg))
-    sys.stderr.write('{} failed\n\n'.format(name))
-
-
-def typename(t: type) -> str:
-    if '.' in str(t):
-        return str(t).split('.')[-1].rstrip("'>")
-    else:
-        return str(t)[8:-2]
-
-
-def match_pattern(s: str, p: str) -> bool:
-    if len(p) == 0:
-        return len(s) == 0
-    elif p[0] == '*':
-        if len(p) == 1:
-            return True
-        else:
-            for i in range(len(s) + 1):
-                if match_pattern(s[i:], p[1:]):
-                    return True
-            return False
-    elif len(s) == 0:
-        return False
-    else:
-        return s[0] == p[0] and match_pattern(s[1:], p[1:])
-
-
-def clean_traceback(tb: List[str]) -> List[str]:
-    # Remove clutter from the traceback.
-    start = 0
-    for i, s in enumerate(tb):
-        if '\n    test.run()\n' in s or '\n    self.func()\n' in s:
-            start = i + 1
-    tb = tb[start:]
-    for f in ['assert_equal', 'assert_not_equal', 'assert_type',
-              'assert_raises', 'assert_true']:
-        if tb != [] and ', in {}\n'.format(f) in tb[-1]:
-            tb = tb[:-1]
-    return tb
+# This page intentionally left blank
diff --git a/mypy/myunit/__main__.py b/mypy/myunit/__main__.py
index 34098d40648d..de26b70e84d2 100644
--- a/mypy/myunit/__main__.py
+++ b/mypy/myunit/__main__.py
@@ -4,6 +4,6 @@
 Usually used as a slave by runtests.py, but can be used directly.
 """
 
-from mypy.myunit import main
+from mypy.myunit.main import main
 
 main()
diff --git a/mypy/myunit/assertions.py b/mypy/myunit/assertions.py
new file mode 100644
index 000000000000..f59413b6a90d
--- /dev/null
+++ b/mypy/myunit/assertions.py
@@ -0,0 +1,30 @@
+def fail(msg: str = None) -> None:
+    from mypy.myunit.errors import AssertionFailure
+    raise AssertionFailure(msg)
+
+
+def assert_true(b: bool, msg: str = None) -> None:
+    if not b:
+        fail(msg)
+
+
+def assert_false(b: bool, msg: str = None) -> None:
+    if b:
+        fail(msg)
+
+
+def _good_repr(obj: object) -> str:
+    if isinstance(obj, str):
+        if obj.count('\n') > 1:
+            bits = ["'''\\"]
+            for line in obj.split('\n'):
+                # force repr to use ' not ", then cut it off
+                bits.append(repr('"' + line)[2:-1])
+            bits[-1] += "'''"
+            return '\n'.join(bits)
+    return repr(obj)
+
+
+def assert_equal(a: object, b: object, fmt: str = '{} != {}') -> None:
+    if a != b:
+        fail(fmt.format(_good_repr(a), _good_repr(b)))
diff --git a/mypy/myunit/errors.py b/mypy/myunit/errors.py
new file mode 100644
index 000000000000..fc06d2a5bed6
--- /dev/null
+++ b/mypy/myunit/errors.py
@@ -0,0 +1,7 @@
+class MyunitException(Exception): pass
+
+
+class AssertionFailure(MyunitException): pass
+
+
+class SkipTestCaseException(MyunitException): pass
diff --git a/mypy/myunit/ick.py b/mypy/myunit/ick.py
new file mode 100644
index 000000000000..3c7ff591b79a
--- /dev/null
+++ b/mypy/myunit/ick.py
@@ -0,0 +1,6 @@
+"""Ick, mutable globals!
+"""
+
+# TODO remove global state
+APPEND_TESTCASES = ''
+UPDATE_TESTCASES = False
diff --git a/mypy/myunit/main.py b/mypy/myunit/main.py
new file mode 100644
index 000000000000..22a1d6255291
--- /dev/null
+++ b/mypy/myunit/main.py
@@ -0,0 +1,90 @@
+from typing import Callable, List, cast
+
+import importlib
+import sys
+
+from mypy.myunit.suite import Suite
+from mypy.myunit import ick
+from mypy.myunit.run import run_test_recursive
+from mypy.myunit import run
+
+
+def add_suites_from_module(suites: List[Suite], mod_name: str) -> None:
+    mod = importlib.import_module(mod_name)
+    got_suite = False
+    for suite in mod.__dict__.values():
+        if isinstance(suite, type) and issubclass(suite, Suite) and suite is not Suite:
+            got_suite = True
+            suites.append(cast(Callable[[], Suite], suite)())
+    if not got_suite:
+        # Sanity check in case e.g. it uses unittest instead of a myunit.
+        # The codecs tests do since they need to be python2-compatible.
+        sys.exit('Test module %s had no test!' % mod_name)
+
+
+class ListSuite(Suite):
+    def __init__(self, suites: List[Suite]) -> None:
+        for suite in suites:
+            mod_name = type(suite).__module__.replace('.', '_')
+            mod_name = mod_name.replace('mypy_', '')
+            mod_name = mod_name.replace('test_', '')
+            mod_name = mod_name.strip('_').replace('__', '_')
+            type_name = type(suite).__name__
+            name = 'test_%s_%s' % (mod_name, type_name)
+            setattr(self, name, suite)
+        super().__init__()
+
+
+def main(args: List[str] = None) -> None:
+    if not args:
+        args = sys.argv[1:]
+    run.is_verbose = False
+    run.is_quiet = False
+    suites = []  # type: List[Suite]
+    run.patterns = []
+    i = 0
+    while i < len(args):
+        a = args[i]
+        if a == '-v':
+            run.is_verbose = True
+        elif a == '-q':
+            run.is_quiet = True
+        elif a == '-u':
+            ick.APPEND_TESTCASES = '.new'
+            ick.UPDATE_TESTCASES = True
+        elif a == '-i':
+            ick.APPEND_TESTCASES = ''
+            ick.UPDATE_TESTCASES = True
+        elif a == '-m':
+            i += 1
+            if i == len(args):
+                sys.exit('-m requires an argument')
+            add_suites_from_module(suites, args[i])
+        elif not a.startswith('-'):
+            run.patterns.append(a)
+        else:
+            sys.exit('Usage: python -m mypy.myunit [-v] [-q] [-u | -i]'
+                    + ' -m test.module [-m test.module ...] [filter ...]')
+        i += 1
+    if len(run.patterns) == 0:
+        run.patterns.append('*')
+    if not suites:
+        sys.exit('At least one -m argument is required')
+
+    t = ListSuite(suites)
+    num_total, num_fail, num_skip = run_test_recursive(t, 0, 0, 0, '', 0)
+
+    skip_msg = ''
+    if num_skip > 0:
+        skip_msg = ', {} skipped'.format(num_skip)
+
+    if num_fail == 0:
+        if not run.is_quiet:
+            print('%d test cases run%s, all passed.' % (num_total, skip_msg))
+            print('*** OK ***')
+    else:
+        sys.stderr.write('%d/%d test cases failed%s.\n' % (num_fail,
+                                                           num_total,
+                                                           skip_msg))
+        sys.stderr.write('*** FAILURE ***\n')
+        sys.exit(1)
diff --git a/mypy/myunit/run.py b/mypy/myunit/run.py
new file mode 100644
index 000000000000..4e21f5d15d4c
--- /dev/null
+++ b/mypy/myunit/run.py
@@ -0,0 +1,123 @@
+from typing import Any, List, Tuple, Union, cast
+
+import sys
+import traceback
+
+from mypy.myunit.errors import SkipTestCaseException
+from mypy.myunit.suite import Suite, TestCase, TestUnion, typename
+
+# TODO remove global state
+is_verbose = False
+is_quiet = False
+patterns = []  # type: List[str]
+
+
+def run_test_recursive(test: Union[Suite, TestUnion],
+                       num_total: int, num_fail: int, num_skip: int,
+                       prefix: str, depth: int) -> Tuple[int, int, int]:
+    if isinstance(test, TestCase):
+        name = prefix + test.name
+        for pattern in patterns:
+            if match_pattern(name, pattern):
+                match = True
+                break
+        else:
+            match = False
+        if match:
+            is_fail, is_skip = run_single_test(name, test)
+            if is_fail: num_fail += 1
+            if is_skip: num_skip += 1
+            num_total += 1
+    else:
+        suite = None  # type: Suite
+        suite_prefix = ''
+        if isinstance(test, tuple):
+            suite_prefix, suite = cast(Tuple[str, Suite], test)
+        else:
+            suite = cast(Suite, test)
+            suite_prefix = suite.prefix
+
+        for stest in suite.cases():
+            new_prefix = prefix
+            if depth > 0:
+                new_prefix = prefix + suite_prefix
+            num_total, num_fail, num_skip = run_test_recursive(
+                stest, num_total, num_fail, num_skip, new_prefix, depth + 1)
+    return num_total, num_fail, num_skip
+
+
+def run_single_test(name: str, test: TestCase) -> Tuple[bool, bool]:
+    if is_verbose:
+        sys.stderr.write(name)
+        sys.stderr.flush()
+
+    test.set_up()  # FIX: check exceptions
+    exc_traceback = None  # type: Any
+    try:
+        test.run()
+    except Exception:
+        exc_type, exc_value, exc_traceback = sys.exc_info()
+    test.tear_down()  # FIX: check exceptions
+
+    if exc_traceback:
+        if isinstance(exc_value, SkipTestCaseException):
+            if is_verbose:
+                sys.stderr.write(' (skipped)\n')
+            return False, True
+        else:
+            handle_failure(name, exc_type, exc_value, exc_traceback)
+            return True, False
+    elif is_verbose:
+        sys.stderr.write('\n')
+
+    return False, False
+
+
+def handle_failure(name, exc_type, exc_value, exc_traceback) -> None:
+    # Report failed test case.
+    if is_verbose:
+        sys.stderr.write('\n\n')
+    msg = ''
+    if exc_value.args and exc_value.args[0]:
+        msg = ': ' + str(exc_value)
+    else:
+        msg = ''
+    sys.stderr.write('Traceback (most recent call last):\n')
+    tb = traceback.format_tb(exc_traceback)
+    tb = clean_traceback(tb)
+    for s in tb:
+        sys.stderr.write(s)
+    exception = typename(exc_type)
+    sys.stderr.write('{}{}\n\n'.format(exception, msg))
+    sys.stderr.write('{} failed\n\n'.format(name))
+
+
+def match_pattern(s: str, p: str) -> bool:
+    if len(p) == 0:
+        return len(s) == 0
+    elif p[0] == '*':
+        if len(p) == 1:
+            return True
+        else:
+            for i in range(len(s) + 1):
+                if match_pattern(s[i:], p[1:]):
+                    return True
+            return False
+    elif len(s) == 0:
+        return False
+    else:
+        return s[0] == p[0] and match_pattern(s[1:], p[1:])
+
+
+def clean_traceback(tb: List[str]) -> List[str]:
+    # Remove clutter from the traceback.
+    start = 0
+    for i, s in enumerate(tb):
+        if '\n    test.run()\n' in s or '\n    self.func()\n' in s:
+            start = i + 1
+    tb = tb[start:]
+    for f in ['assert_equal', 'assert_not_equal', 'assert_type',
+              'assert_raises', 'assert_true']:
+        if tb != [] and ', in {}\n'.format(f) in tb[-1]:
+            tb = tb[:-1]
+    return tb
diff --git a/mypy/myunit/suite.py b/mypy/myunit/suite.py
new file mode 100644
index 000000000000..fe2d1b94a4c4
--- /dev/null
+++ b/mypy/myunit/suite.py
@@ -0,0 +1,79 @@
+from typing import Callable, List, Tuple, Union
+
+import os
+import tempfile
+
+from mypy.myunit.errors import SkipTestCaseException
+
+
+class TestCase:
+    def __init__(self, name: str, suite: 'Suite' = None,
+                 func: Callable[[], None] = None) -> None:
+        self.func = func
+        self.name = name
+        self.suite = suite
+        self.old_cwd = None  # type: str
+        self.tmpdir = None  # type: tempfile.TemporaryDirectory
+
+    def run(self) -> None:
+        if self.func:
+            self.func()
+
+    def set_up(self) -> None:
+        self.old_cwd = os.getcwd()
+        self.tmpdir = tempfile.TemporaryDirectory(prefix='mypy-test-',
+                dir=os.path.abspath('tmp-test-dirs'))
+        os.chdir(self.tmpdir.name)
+        os.mkdir('tmp')
+        if self.suite:
+            self.suite.set_up()
+
+    def tear_down(self) -> None:
+        if self.suite:
+            self.suite.tear_down()
+        os.chdir(self.old_cwd)
+        self.tmpdir.cleanup()
+        self.old_cwd = None
+        self.tmpdir = None
+
+
+TestUnion = Union[TestCase, Tuple[str, 'Suite']]
+
+
+class Suite:
+    def __init__(self) -> None:
+        self.prefix = typename(type(self)) + '.'
+        self._test_cases = []  # type: List[TestUnion]
+        self.init()
+
+    def set_up(self) -> None:
+        pass
+
+    def tear_down(self) -> None:
+        pass
+
+    def init(self) -> None:
+        for m in dir(self):
+            if m.startswith('test'):
+                t = getattr(self, m)
+                if isinstance(t, Suite):
+                    self.add_test((m + '.', t))
+                else:
+                    assert callable(t), '%s.%s is %s' % (type(self).__name__, m, type(t).__name__)
+                    self.add_test(TestCase(m, self, t))
+
+    def add_test(self, test: TestUnion) -> None:
+        self._test_cases.append(test)
+
+    def cases(self) -> List[TestUnion]:
+        return self._test_cases[:]
+
+    def skip(self) -> None:
+        raise SkipTestCaseException()
+
+
+def typename(t: type) -> str:
+    if '.' in str(t):
+        return str(t).split('.')[-1].rstrip("'>")
+    else:
+        return str(t)[8:-2]
diff --git a/mypy/test/data.py b/mypy/test/data.py
index 73e6b9db35bf..bedb76995259 100644
--- a/mypy/test/data.py
+++ b/mypy/test/data.py
@@ -8,7 +8,8 @@
 
 from typing import Callable, List, Tuple
 
-from mypy.myunit import TestCase, SkipTestCaseException
+from mypy.myunit.errors import SkipTestCaseException
+from mypy.myunit.suite import TestCase
 
 
 def parse_test_cases(
diff --git a/mypy/test/helpers.py b/mypy/test/helpers.py
index b6b1e5a850cf..9fbefea2997e 100644
--- a/mypy/test/helpers.py
+++ b/mypy/test/helpers.py
@@ -5,7 +5,7 @@
 from typing import List, Dict, Tuple
 
 from mypy import defaults
-from mypy.myunit import AssertionFailure
+from mypy.myunit.errors import AssertionFailure
 from mypy.test import config
 
 
diff --git a/mypy/test/testcheck.py b/mypy/test/testcheck.py
index 4fc83b1411f0..1033ea4fd1cd 100644
--- a/mypy/test/testcheck.py
+++ b/mypy/test/testcheck.py
@@ -7,8 +7,8 @@
 from typing import Tuple
 
 from mypy import build
-import mypy.myunit  # for mutable globals (ick!)
-from mypy.myunit import Suite
+from mypy.myunit import ick  # for mutable globals (ick!)
+from mypy.myunit.suite import Suite
 from mypy.test.config import test_temp_dir, test_data_prefix
 from mypy.test.data import parse_test_cases
 from mypy.test.helpers import (
@@ -78,8 +78,8 @@ def run_test(self, testcase):
         except CompileError as e:
             a = normalize_error_messages(e.messages)
 
-        if testcase.output != a and mypy.myunit.UPDATE_TESTCASES:
-            update_testcase_output(testcase, a, mypy.myunit.APPEND_TESTCASES)
+        if testcase.output != a and ick.UPDATE_TESTCASES:
+            update_testcase_output(testcase, a, ick.APPEND_TESTCASES)
 
         assert_string_arrays_equal(
             testcase.output, a,
diff --git a/mypy/test/testdocstring.py b/mypy/test/testdocstring.py
index 9a6b67220007..75d7711fb056 100644
--- a/mypy/test/testdocstring.py
+++ b/mypy/test/testdocstring.py
@@ -1,6 +1,7 @@
 """Test cases for finding type annotations in docstrings."""
 
-from mypy.myunit import Suite, assert_equal
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.docstring import parse_docstring, scrubtype
 
 
diff --git a/mypy/test/testinfer.py b/mypy/test/testinfer.py
index 58d3b0b3a661..6c56a1d94228 100644
--- a/mypy/test/testinfer.py
+++ b/mypy/test/testinfer.py
@@ -2,7 +2,8 @@
 
 import typing
 
-from mypy.myunit import Suite, assert_equal, assert_true
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.checkexpr import map_actuals_to_formals
 from mypy.nodes import ARG_POS, ARG_OPT, ARG_STAR, ARG_STAR2, ARG_NAMED
 from mypy.types import AnyType, TupleType
diff --git a/mypy/test/testlex.py b/mypy/test/testlex.py
index 9a38c5d7677f..e374506e4ceb 100644
--- a/mypy/test/testlex.py
+++ b/mypy/test/testlex.py
@@ -2,7 +2,8 @@
 
 import typing
 
-from mypy.myunit import Suite, assert_equal
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.lex import lex
 
 
diff --git a/mypy/test/testparse.py b/mypy/test/testparse.py
index 56b7523ad4cd..f3f0752ab0ba 100644
--- a/mypy/test/testparse.py
+++ b/mypy/test/testparse.py
@@ -7,7 +7,8 @@
 import typing
 
 from mypy import defaults
-from mypy.myunit import Suite, AssertionFailure
+from mypy.myunit.errors import AssertionFailure
+from mypy.myunit.suite import Suite
 from mypy.test.helpers import assert_string_arrays_equal
 from mypy.test.data import parse_test_cases
 from mypy.test import config
diff --git a/mypy/test/testpythoneval.py b/mypy/test/testpythoneval.py
index 07a4a0dc4f47..3d165becc7e0 100644
--- a/mypy/test/testpythoneval.py
+++ b/mypy/test/testpythoneval.py
@@ -17,7 +17,8 @@
 
 import typing
 
-from mypy.myunit import Suite, SkipTestCaseException
+from mypy.myunit.errors import SkipTestCaseException
+from mypy.myunit.suite import Suite
 from mypy.test.config import test_data_prefix, test_temp_dir
 from mypy.test.data import parse_test_cases
 from mypy.test.helpers import assert_string_arrays_equal
diff --git a/mypy/test/testsemanal.py b/mypy/test/testsemanal.py
index 3a9c14bccce3..3cd51be61d07 100644
--- a/mypy/test/testsemanal.py
+++ b/mypy/test/testsemanal.py
@@ -5,7 +5,7 @@
 from typing import Dict, List
 
 from mypy import build
-from mypy.myunit import Suite
+from mypy.myunit.suite import Suite
 from mypy.test.helpers import assert_string_arrays_equal, testfile_pyversion
 from mypy.test.data import parse_test_cases
 from mypy.test.config import test_data_prefix, test_temp_dir
diff --git a/mypy/test/testsolve.py b/mypy/test/testsolve.py
index b84bb1714f50..f5d9e15e2840 100644
--- a/mypy/test/testsolve.py
+++ b/mypy/test/testsolve.py
@@ -2,10 +2,11 @@
 
 import typing
 
-from mypy.myunit import Suite, assert_equal
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.constraints import SUPERTYPE_OF, SUBTYPE_OF, Constraint
 from mypy.solve import solve_constraints
-from mypy.typefixture import TypeFixture
+from mypy.test.typefixture import TypeFixture
 
 
 class SolveSuite(Suite):
diff --git a/mypy/test/teststubgen.py b/mypy/test/teststubgen.py
index 893659d2f6cf..ddfbdd2e741b 100644
--- a/mypy/test/teststubgen.py
+++ b/mypy/test/teststubgen.py
@@ -9,7 +9,9 @@
 
 import typing
 
-from mypy.myunit import Suite, AssertionFailure, assert_equal
+from mypy.myunit.assertions import *
+from mypy.myunit.errors import AssertionFailure
+from mypy.myunit.suite import Suite
 from mypy.test.helpers import assert_string_arrays_equal
 from mypy.test.data import parse_test_cases
 from mypy.test import config
@@ -94,11 +96,11 @@ def test_infer_sig_from_docstring(self):
 
 
 class StubgenPythonSuite(Suite):
-    test_data_files = ['stubgen.test']
+    data_files = ['stubgen.test']
 
     def cases(self):
         c = []
-        for path in self.test_data_files:
+        for path in self.data_files:
             c += parse_test_cases(os.path.join(config.test_data_prefix, path), test_stubgen)
         return c
 
diff --git a/mypy/test/testsubtypes.py b/mypy/test/testsubtypes.py
index e8a4121c7682..2e106039e13d 100644
--- a/mypy/test/testsubtypes.py
+++ b/mypy/test/testsubtypes.py
@@ -1,7 +1,8 @@
-from mypy.myunit import Suite, assert_true
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.nodes import CONTRAVARIANT, INVARIANT, COVARIANT
 from mypy.subtypes import is_subtype
-from mypy.typefixture import TypeFixture, InterfaceTypeFixture
+from mypy.test.typefixture import TypeFixture, InterfaceTypeFixture
 
 
 class SubtypingSuite(Suite):
diff --git a/mypy/test/testtransform.py b/mypy/test/testtransform.py
index eaab12cb1de8..bb7a413aa882 100644
--- a/mypy/test/testtransform.py
+++ b/mypy/test/testtransform.py
@@ -5,7 +5,7 @@
 from typing import Dict, List
 
 from mypy import build
-from mypy.myunit import Suite
+from mypy.myunit.suite import Suite
 from mypy.test.helpers import assert_string_arrays_equal, testfile_pyversion
 from mypy.test.data import parse_test_cases
 from mypy.test.config import test_data_prefix, test_temp_dir
diff --git a/mypy/test/testtypegen.py b/mypy/test/testtypegen.py
index dc1961544238..32f7e9275bda 100644
--- a/mypy/test/testtypegen.py
+++ b/mypy/test/testtypegen.py
@@ -6,7 +6,7 @@
 import typing
 
 from mypy import build
-from mypy.myunit import Suite
+from mypy.myunit.suite import Suite
 from mypy.test import config
 from mypy.test.data import parse_test_cases
 from mypy.test.helpers import assert_string_arrays_equal
diff --git a/mypy/test/testtypes.py b/mypy/test/testtypes.py
index ec0c3ef8bafb..aaed7c87a78d 100644
--- a/mypy/test/testtypes.py
+++ b/mypy/test/testtypes.py
@@ -2,9 +2,8 @@
 
 from typing import List
 
-from mypy.myunit import (
-    Suite, assert_equal, assert_true, assert_false
-)
+from mypy.myunit.assertions import *
+from mypy.myunit.suite import Suite
 from mypy.erasetype import erase_type
 from mypy.expandtype import expand_type
 from mypy.join import join_types
@@ -16,7 +15,7 @@
 from mypy.nodes import ARG_POS, ARG_OPT, ARG_STAR, CONTRAVARIANT, INVARIANT, COVARIANT
 from mypy.replacetvars import replace_type_vars
 from mypy.subtypes import is_subtype, is_more_precise, is_proper_subtype
-from mypy.typefixture import TypeFixture, InterfaceTypeFixture
+from mypy.test.typefixture import TypeFixture, InterfaceTypeFixture
 
 
 class TypesSuite(Suite):
diff --git a/mypy/typefixture.py b/mypy/test/typefixture.py
similarity index 100%
rename from mypy/typefixture.py
rename to mypy/test/typefixture.py
diff --git a/runtests.py b/runtests.py
index 462fa1491369..4cd6b3234b23 100755
--- a/runtests.py
+++ b/runtests.py
@@ -205,8 +205,8 @@ def add_myunit(driver: Driver) -> None:
         mod = file_to_module(f)
         if '.codec.test.' in mod:
             # myunit is Python3 only.
-            driver.add_python_mod('unittest %s' % mod, 'unittest', mod)
-            driver.add_python2('unittest %s' % mod, '-m', 'unittest', mod)
+            driver.add_python_mod('unittest %s' % mod, 'unittest', '-q', mod)
+            driver.add_python2('unittest %s' % mod, '-m', 'unittest', '-q', mod)
         elif mod == 'mypy.test.testpythoneval':
             # Run Python evaluation integration tests separetely since they are much slower
             # than proper unit tests.
@@ -326,6 +326,8 @@ def main() -> None:
     # empty string is a substring of all names
     if not whitelist:
         whitelist.append('')
+    if not arglist:
+        arglist.append('-q')
 
     driver = Driver(whitelist=whitelist, blacklist=blacklist, arglist=arglist,
             verbosity=verbosity, xfail=[])
diff --git a/scripts/myunit b/scripts/myunit
index 43fce063f5a2..a8a67b87d4f0 100755
--- a/scripts/myunit
+++ b/scripts/myunit
@@ -4,6 +4,6 @@
 Usually used as a slave by runtests.py, but can be used directly.
 """
 
-from mypy.myunit import main
+from mypy.myunit.main import main
 
 main()
diff --git a/setup.cfg b/setup.cfg
index 4818cec154a6..0d28dd19e8f1 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -7,4 +7,5 @@ exclude = mypy/codec/*,mypy/test/data/lib-stub/*,mypy/test/data/fixtures/*
 #   F401: unused identifiers (useless, as it doesn't see inside # type: comments)
 #   W601: has_key() deprecated (false positives)
 #   E701: multiple statements on one line (colon) (we use this for classes with empty body)
-ignore = E251,E128,F401,W601,E701
+#   F403: 'from foo import *' used; unable to detect undefined names (mypy checks this better)
+ignore = E251,E128,F401,W601,E701,F403