diff --git a/mypy/fastparse.py b/mypy/fastparse.py
index 4a0e34d7ba149..688cd9b20928d 100644
--- a/mypy/fastparse.py
+++ b/mypy/fastparse.py
@@ -74,7 +74,7 @@ def parse(source: Union[str, bytes],
           module: Optional[str],
           errors: Optional[Errors] = None,
           options: Optional[Options] = None,
-          plugin: Plugin = None	) -> MypyFile:
+          plugin: Optional[Plugin] = None) -> MypyFile:
 
     """Parse a source file, without doing any semantic analysis.
 
@@ -87,6 +87,8 @@ def parse(source: Union[str, bytes],
         raise_on_error = True
     if options is None:
         options = Options()
+    if plugin is None:
+        plugin = Plugin(options)
     errors.set_file(fnam, module)
     is_stub_file = fnam.endswith('.pyi')
     try:
@@ -137,8 +139,9 @@ def parse_docstring(hook: Callable[[DocstringParserContext], TypeMap], docstring
     """
     type_map = hook(DocstringParserContext(docstring, line, errors))
     if type_map:
-        arg_types = [type_map.pop(name, AnyType()) for name in arg_names]
-        return_type = type_map.pop('return', AnyType())
+        arg_types = [type_map.pop(name, AnyType(TypeOfAny.unannotated))
+                     for name in arg_names]
+        return_type = type_map.pop('return', AnyType(TypeOfAny.unannotated))
         if type_map:
             errors.report(line, 0,
                           TYPE_COMMENT_DOCSTRING_ERROR.format(list(type_map)))
diff --git a/mypy/fastparse2.py b/mypy/fastparse2.py
index 5c1bb8b9d890b..6ebcc339d77e5 100644
--- a/mypy/fastparse2.py
+++ b/mypy/fastparse2.py
@@ -83,7 +83,7 @@ def parse(source: Union[str, bytes],
           module: Optional[str],
           errors: Optional[Errors] = None,
           options: Optional[Options] = None,
-          plugin: Plugin = None) -> MypyFile:
+          plugin: Optional[Plugin] = None) -> MypyFile:
     """Parse a source file, without doing any semantic analysis.
 
     Return the parse tree. If errors is not provided, raise ParseError
@@ -95,6 +95,8 @@ def parse(source: Union[str, bytes],
         raise_on_error = True
     if options is None:
         options = Options()
+    if plugin is None:
+        plugin = Plugin(options)
     errors.set_file(fnam, module)
     is_stub_file = fnam.endswith('.pyi')
     try:
diff --git a/mypy/parse.py b/mypy/parse.py
index a1fd8fe0f0059..cdfadde25dfba 100644
--- a/mypy/parse.py
+++ b/mypy/parse.py
@@ -11,7 +11,7 @@ def parse(source: Union[str, bytes],
           module: Optional[str],
           errors: Optional[Errors],
           options: Options,
-          plugin: Plugin) -> MypyFile:
+          plugin: Optional[Plugin]) -> MypyFile:
     """Parse a source file, without doing any semantic analysis.
 
     Return the parse tree. If errors is not provided, raise ParseError
diff --git a/mypy/plugin.py b/mypy/plugin.py
index 5dbe05ec709d8..ff70a7111c26b 100644
--- a/mypy/plugin.py
+++ b/mypy/plugin.py
@@ -125,6 +125,7 @@ def fail(self, msg: str, ctx: Context, serious: bool = False, *,
         ('cls', ClassDef),       # The class definition
         ('reason', Expression),  # The expression being applied (decorator, metaclass, base class)
         ('api', SemanticAnalyzerPluginInterface)
+    ])
 
 # A context for a hook that extracts type annotations from docstrings.
 #