diff --git a/Lib/contextlib.py b/Lib/contextlib.py
index c53b35e8d5..a410696f15 100644
--- a/Lib/contextlib.py
+++ b/Lib/contextlib.py
@@ -54,35 +54,9 @@ class ContextDecorator(object):
         return inner
 
 
-class _GeneratorContextManagerBase:
-    """Shared functionality for @contextmanager and @asynccontextmanager."""
-
-    def __init__(self, func, args, kwds):
-        self.gen = func(*args, **kwds)
-        self.func, self.args, self.kwds = func, args, kwds
-        # Issue 19330: ensure context manager instances have good docstrings
-        doc = getattr(func, "__doc__", None)
-        if doc is None:
-            doc = type(self).__doc__
-        self.__doc__ = doc
-        # Unfortunately, this still doesn't provide good help output when
-        # inspecting the created context manager instances, since pydoc
-        # currently bypasses the instance docstring and shows the docstring
-        # for the class instead.
-        # See http://bugs.python.org/issue19404 for more details.
-
-
-class _GeneratorContextManager(_GeneratorContextManagerBase,
-                               AbstractContextManager,
-                               ContextDecorator):
+class _GeneratorContextManager(AbstractContextManager):
     """Helper for @contextmanager decorator."""
 
-    def _recreate_cm(self):
-        # _GCM instances are one-shot context managers, so the
-        # CM must be recreated each time a decorated function is
-        # called
-        return self.__class__(self.func, self.args, self.kwds)
-
     def __enter__(self):
         try:
             return next(self.gen)
@@ -137,9 +111,50 @@ class _GeneratorContextManager(_GeneratorContextManagerBase,
             raise RuntimeError("generator didn't stop after throw()")
 
 
-class _AsyncGeneratorContextManager(_GeneratorContextManagerBase):
+def _set_docstring(wrapper, wrapped):
+    # Issue 19330: ensure context manager instances have good docstrings
+    doc = getattr(wrapped, "__doc__", None)
+    if doc is None:
+        doc = type(wrapper).__doc__
+    wrapper.__doc__ = doc
+    # Unfortunately, this still doesn't provide good help output when
+    # inspecting the created context manager instances, since pydoc
+    # currently bypasses the instance docstring and shows the docstring
+    # for the class instead.
+    # See http://bugs.python.org/issue19404 for more details.
+
+
+class _GeneratorContextManagerDecorator(_GeneratorContextManager,
+                                        ContextDecorator):
+    """Helper for @contextmanager decorator."""
+
+    def __init__(self, func, args, kwds):
+        self.func, self.args, self.kwds = func, args, kwds
+        _set_docstring(self, func)
+
+    def __call__(self, func):
+        func1, args1, kwds1 = self.func, self.args, self.kwds
+        @wraps(func)
+        def inner(*args, **kwds):
+            cm = _GeneratorContextManager()
+            cm.gen = func1(*args1, **kwds1)
+            with cm:
+                return func(*args, **kwds)
+        return inner
+
+    def __enter__(self):
+        self.gen = self.func(*self.args, **self.kwds)
+        del self.func, self.args, self.kwds
+        return super().__enter__()
+
+
+class _AsyncGeneratorContextManager:
     """Helper for @asynccontextmanager."""
 
+    def __init__(self, func, args, kwds):
+        self.gen = func(*args, **kwds)
+        _set_docstring(self, func)
+
     async def __aenter__(self):
         try:
             return await self.gen.__anext__()
@@ -211,7 +226,7 @@ def contextmanager(func):
     """
     @wraps(func)
     def helper(*args, **kwds):
-        return _GeneratorContextManager(func, args, kwds)
+        return _GeneratorContextManagerDecorator(func, args, kwds)
     return helper