diff --git a/CHANGES b/CHANGES
index b3eb60219..db6ec12e7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -101,6 +101,8 @@ Bugs fixed
 * #2707: (latex) the column width is badly computed for tabular
 * #2799: Sphinx installs roles and directives automatically on importing sphinx
   module.  Now Sphinx installs them on running application.
+* `sphinx.ext.autodoc` crashes if target code imports * from mock modules
+  by `autodoc_mock_imports`.
 
 Documentation
 -------------
diff --git a/sphinx/ext/autodoc.py b/sphinx/ext/autodoc.py
index 08bc99cdf..a0480341c 100644
--- a/sphinx/ext/autodoc.py
+++ b/sphinx/ext/autodoc.py
@@ -86,17 +86,21 @@ class Options(dict):
 
 class _MockModule(object):
     """Used by autodoc_mock_imports."""
+    __file__ = '/dev/null'
+    __path__ = '/dev/null'
+
     def __init__(self, *args, **kwargs):
-        pass
+        self.__all__ = []
 
     def __call__(self, *args, **kwargs):
         return _MockModule()
 
+    def _append_submodule(self, submod):
+        self.__all__.append(submod)
+
     @classmethod
     def __getattr__(cls, name):
-        if name in ('__file__', '__path__'):
-            return '/dev/null'
-        elif name[0] == name[0].upper():
+        if name[0] == name[0].upper():
             # Not very good, we assume Uppercase names are classes...
             mocktype = type(name, (), {})
             mocktype.__module__ = __name__
@@ -109,9 +113,12 @@ def mock_import(modname):
     if '.' in modname:
         pkg, _n, mods = modname.rpartition('.')
         mock_import(pkg)
-    mod = _MockModule()
-    sys.modules[modname] = mod
-    return mod
+        if isinstance(sys.modules[pkg], _MockModule):
+            sys.modules[pkg]._append_submodule(mods)
+
+    if modname not in sys.modules:
+        mod = _MockModule()
+        sys.modules[modname] = mod
 
 
 ALL = object()
@@ -514,7 +521,7 @@ class Documenter(object):
         try:
             dbg('[autodoc] import %s', self.modname)
             for modname in self.env.config.autodoc_mock_imports:
-                dbg('[autodoc] adding a mock module %s!', self.modname)
+                dbg('[autodoc] adding a mock module %s!', modname)
                 mock_import(modname)
             __import__(self.modname)
             parent = None
diff --git a/tests/roots/test-ext-autodoc/autodoc_dummy_module.py b/tests/roots/test-ext-autodoc/autodoc_dummy_module.py
new file mode 100644
index 000000000..c05d96e0d
--- /dev/null
+++ b/tests/roots/test-ext-autodoc/autodoc_dummy_module.py
@@ -0,0 +1,6 @@
+from dummy import *
+
+
+def test():
+    """Dummy function using dummy.*"""
+    dummy_function()
diff --git a/tests/roots/test-ext-autodoc/conf.py b/tests/roots/test-ext-autodoc/conf.py
new file mode 100644
index 000000000..01e6dcc75
--- /dev/null
+++ b/tests/roots/test-ext-autodoc/conf.py
@@ -0,0 +1,12 @@
+import sys, os
+
+sys.path.insert(0, os.path.abspath('.'))
+
+extensions = ['sphinx.ext.autodoc']
+
+# The suffix of source filenames.
+source_suffix = '.rst'
+
+autodoc_mock_imports = [
+    'dummy'
+]
diff --git a/tests/roots/test-ext-autodoc/contents.rst b/tests/roots/test-ext-autodoc/contents.rst
new file mode 100644
index 000000000..b808eafda
--- /dev/null
+++ b/tests/roots/test-ext-autodoc/contents.rst
@@ -0,0 +1,3 @@
+
+.. automodule:: autodoc_dummy_module
+   :members:
diff --git a/tests/test_ext_autodoc.py b/tests/test_ext_autodoc.py
new file mode 100644
index 000000000..dad7521af
--- /dev/null
+++ b/tests/test_ext_autodoc.py
@@ -0,0 +1,25 @@
+# -*- coding: utf-8 -*-
+"""
+    test_autodoc
+    ~~~~~~~~~~~~
+
+    Test the autodoc extension.
+
+    :copyright: Copyright 2007-2016 by the Sphinx team, see AUTHORS.
+    :license: BSD, see LICENSE for details.
+"""
+
+import pickle
+from docutils import nodes
+from sphinx import addnodes
+from util import with_app
+
+
+@with_app(buildername='dummy', testroot='ext-autodoc')
+def test_autodoc(app, status, warning):
+    app.builder.build_all()
+
+    content = pickle.loads((app.doctreedir / 'contents.doctree').bytes())
+    assert isinstance(content[3], addnodes.desc)
+    assert content[3][0].astext() == 'autodoc_dummy_module.test'
+    assert content[3][1].astext() == 'Dummy function using dummy.*'