diff --git a/CHANGES b/CHANGES
index 6ad017732..d7d9e4b8d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -45,6 +45,8 @@ New features added
 * sphinx.doc.autodoc has a new event ``autodoc-process-signature``
   that allows tuning function signature introspection.
 
+* Respect __all__ when autodocumenting module members.
+
 * Glossary entries are now automatically added to the index.
 
 * Added ``exclude_dirnames`` config value that can be used to exclude
diff --git a/sphinx/ext/autodoc.py b/sphinx/ext/autodoc.py
index 0df3186a8..450169f2b 100644
--- a/sphinx/ext/autodoc.py
+++ b/sphinx/ext/autodoc.py
@@ -498,10 +498,14 @@ class RstGenerator(object):
         if _all:
             # unqualified :members: given
             if what == 'module':
-                # for implicit module members, check __module__ to avoid documenting
-                # imported objects if __all__ is not defined
-                members_check_module = not hasattr(todoc, '__all__')
-                all_members = inspect.getmembers(todoc)
+                if hasattr(todoc, '__all__'):
+                    members_check_module = False
+                    all_members = inspect.getmembers(todoc, lambda x: x in todoc.__all__)
+                else:
+                    # for implicit module members, check __module__ to avoid
+                    # documenting imported objects
+                    members_check_module = True
+                    all_members = inspect.getmembers(todoc)
             else:
                 if self.options.inherited_members:
                     # getmembers() uses dir() which pulls in members from all