diff --git a/CHANGES b/CHANGES
index 292dffa0e..f35e7ed54 100644
--- a/CHANGES
+++ b/CHANGES
@@ -14,6 +14,8 @@ Bugs fixed
 ----------
 
 * PR#311: sphinx-quickstart does not work on python 3.4.
+* Fix :confval:`autodoc_docstring_signature` not working with signatures
+  in class docstrings.
 
 
 Release 1.3b1 (released Oct 10, 2014)
@@ -127,6 +129,7 @@ Bugs fixed
 
 * #1438: Updated jQuery version from 1.8.3 to 1.11.1.
 * #1568: Fix a crash when a "centered" directive contains a reference.
+* Now sphinx.ext.autodoc works with python-2.5 again.
 * #1563: :meth:`~sphinx.application.Sphinx.add_search_language` raises
   AssertionError for correct type of argument. Thanks to rikoman.
 * #1174: Fix smart quotes being applied inside roles like :rst:role:`program` or
diff --git a/sphinx/ext/autodoc.py b/sphinx/ext/autodoc.py
index 5b0bda17a..c60372242 100644
--- a/sphinx/ext/autodoc.py
+++ b/sphinx/ext/autodoc.py
@@ -945,36 +945,37 @@ class DocstringSignatureMixin(object):
     """
 
     def _find_signature(self, encoding=None):
-        docstrings = Documenter.get_doc(self, encoding)
-        if len(docstrings) != 1:
-            return
-        doclines = docstrings[0]
-        setattr(self, '__new_doclines', doclines)
-        if not doclines:
-            return
-        # match first line of docstring against signature RE
-        match = py_ext_sig_re.match(doclines[0])
-        if not match:
-            return
-        exmod, path, base, args, retann = match.groups()
-        # the base name must match ours
-        if not self.objpath or base != self.objpath[-1]:
-            return
-        # re-prepare docstring to ignore indentation after signature
-        docstrings = Documenter.get_doc(self, encoding, 2)
-        doclines = docstrings[0]
-        # ok, now jump over remaining empty lines and set the remaining
-        # lines as the new doclines
-        i = 1
-        while i < len(doclines) and not doclines[i].strip():
-            i += 1
-        setattr(self, '__new_doclines', doclines[i:])
-        return args, retann
+        docstrings = self.get_doc(encoding)
+        self._new_docstrings = docstrings[:]
+        result = None
+        for i, doclines in enumerate(docstrings):
+            # no lines in docstring, no match
+            if not doclines:
+                continue
+            # match first line of docstring against signature RE
+            match = py_ext_sig_re.match(doclines[0])
+            if not match:
+                continue
+            exmod, path, base, args, retann = match.groups()
+            # the base name must match ours
+            valid_names = [self.objpath[-1]]
+            if isinstance(self, ClassDocumenter):
+                valid_names.append('__init__')
+                if hasattr(self.object, '__mro__'):
+                    valid_names.extend(cls.__name__ for cls in self.object.__mro__)
+            if base not in valid_names:
+                continue
+            # re-prepare docstring to ignore more leading indentation
+            self._new_docstrings[i] = prepare_docstring('\n'.join(doclines[1:]))
+            result = args, retann
+            # don't look any further
+            break
+        return result
 
     def get_doc(self, encoding=None, ignore=1):
-        lines = getattr(self, '__new_doclines', None)
+        lines = getattr(self, '_new_docstrings', None)
         if lines is not None:
-            return [lines]
+            return lines
         return Documenter.get_doc(self, encoding, ignore)
 
     def format_signature(self):
@@ -1046,7 +1047,7 @@ class FunctionDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):
         pass
 
 
-class ClassDocumenter(ModuleLevelDocumenter):
+class ClassDocumenter(DocstringSignatureMixin, ModuleLevelDocumenter):
     """
     Specialized Documenter subclass for classes.
     """
@@ -1098,18 +1099,7 @@ class ClassDocumenter(ModuleLevelDocumenter):
         if self.doc_as_attr:
             return ''
 
-        # get __init__ method signature from __init__.__doc__
-        if self.env.config.autodoc_docstring_signature:
-            # only act if the feature is enabled
-            init_doc = MethodDocumenter(self.directive, '__init__')
-            init_doc.object = self.get_attr(self.object, '__init__', None)
-            init_doc.objpath = ['__init__']
-            result = init_doc._find_signature()
-            if result is not None:
-                # use args only for Class signature
-                return '(%s)' % result[0]
-
-        return ModuleLevelDocumenter.format_signature(self)
+        return DocstringSignatureMixin.format_signature(self)
 
     def add_directive_header(self, sig):
         if self.doc_as_attr:
@@ -1128,6 +1118,10 @@ class ClassDocumenter(ModuleLevelDocumenter):
                               '<autodoc>')
 
     def get_doc(self, encoding=None, ignore=1):
+        lines = getattr(self, '_new_docstrings', None)
+        if lines is not None:
+            return lines
+
         content = self.env.config.autoclass_content
 
         docstrings = []
@@ -1138,18 +1132,8 @@ class ClassDocumenter(ModuleLevelDocumenter):
         # for classes, what the "docstring" is can be controlled via a
         # config value; the default is only the class docstring
         if content in ('both', 'init'):
-            # get __init__ method document from __init__.__doc__
-            if self.env.config.autodoc_docstring_signature:
-                # only act if the feature is enabled
-                init_doc = MethodDocumenter(self.directive, '__init__')
-                init_doc.object = self.get_attr(self.object, '__init__', None)
-                init_doc.objpath = ['__init__']
-                init_doc._find_signature()  # this effects to get_doc() result
-                initdocstring = '\n'.join(
-                    ['\n'.join(l) for l in init_doc.get_doc(encoding)])
-            else:
-                initdocstring = self.get_attr(
-                    self.get_attr(self.object, '__init__', None), '__doc__')
+            initdocstring = self.get_attr(
+                self.get_attr(self.object, '__init__', None), '__doc__')
             # for new-style classes, no __init__ means default __init__
             if (initdocstring is not None and
                 (initdocstring == object.__init__.__doc__ or  # for pypy
diff --git a/sphinx/util/docstrings.py b/sphinx/util/docstrings.py
index 6b66eee9b..ae973d49e 100644
--- a/sphinx/util/docstrings.py
+++ b/sphinx/util/docstrings.py
@@ -34,7 +34,8 @@ def prepare_docstring(s, ignore=1):
         if i < len(lines):
             lines[i] = lines[i].lstrip()
     if margin < sys.maxsize:
-        for i in range(ignore, len(lines)): lines[i] = lines[i][margin:]
+        for i in range(ignore, len(lines)):
+            lines[i] = lines[i][margin:]
     # Remove any leading blank lines.
     while lines and not lines[0]:
         lines.pop(0)
diff --git a/tests/test_autodoc.py b/tests/test_autodoc.py
index 10921b652..96e46196a 100644
--- a/tests/test_autodoc.py
+++ b/tests/test_autodoc.py
@@ -151,9 +151,12 @@ def test_format_signature():
         inst.fullname = name
         inst.doc_as_attr = False  # for class objtype
         inst.object = obj
+        inst.objpath = [name]
         inst.args = args
         inst.retann = retann
-        return inst.format_signature()
+        res = inst.format_signature()
+        print res
+        return res
 
     # no signatures for modules
     assert formatsig('module', 'test', None, None, None) == ''
@@ -186,7 +189,8 @@ def test_format_signature():
         assert formatsig('class', 'C', C, None, None) == '(a, b=None)'
     assert formatsig('class', 'C', D, 'a, b', 'X') == '(a, b) -> X'
 
-    #__init__ have signature at first line of docstring
+    # __init__ have signature at first line of docstring
+    directive.env.config.autoclass_content = 'both'
     class F2:
         '''some docstring for F2.'''
         def __init__(self, *args, **kw):
@@ -197,9 +201,11 @@ def test_format_signature():
             '''
     class G2(F2, object):
         pass
-    for C in (F2, G2):
-        assert formatsig('class', 'C', C, None, None) == \
-            '(a1, a2, kw1=True, kw2=False)'
+
+    assert formatsig('class', 'F2', F2, None, None) == \
+        '(a1, a2, kw1=True, kw2=False)'
+    assert formatsig('class', 'G2', G2, None, None) == \
+        '(a1, a2, kw1=True, kw2=False)'
 
     # test for methods
     class H:
@@ -215,6 +221,7 @@ def test_format_signature():
     assert formatsig('method', 'H.foo', H.foo3, None, None) == r"(d='\\n')"
 
     # test exception handling (exception is caught and args is '')
+    directive.env.config.autodoc_docstring_signature = False
     assert formatsig('function', 'int', int, None, None) == ''
     del _warnings[:]
 
@@ -242,9 +249,14 @@ def test_get_doc():
     def getdocl(objtype, obj, encoding=None):
         inst = AutoDirective._registry[objtype](directive, 'tmp')
         inst.object = obj
+        inst.objpath = [obj.__name__]
+        inst.doc_as_attr = False
+        inst.format_signature()  # handle docstring signatures!
         ds = inst.get_doc(encoding)
         # for testing purposes, concat them and strip the empty line at the end
-        return sum(ds, [])[:-1]
+        res = sum(ds, [])[:-1]
+        print res
+        return res
 
     # objects without docstring
     def f():
@@ -305,7 +317,7 @@ def test_get_doc():
     assert getdocl('class', D) == ['Class docstring', '', 'Init docstring',
                                    '', 'Other', ' lines']
 
-    #__init__ have signature at first line of docstring
+    # __init__ have signature at first line of docstring
     class E:
         """Class docstring"""
         def __init__(self, *args, **kw):
@@ -330,7 +342,7 @@ def test_get_doc():
 
     # signature line in the docstring will be removed when
     # autodoc_docstring_signature == True
-    directive.env.config.autodoc_docstring_signature = True  #default
+    directive.env.config.autodoc_docstring_signature = True  # default
     directive.env.config.autoclass_content = 'class'
     assert getdocl('class', E) == ['Class docstring']
     directive.env.config.autoclass_content = 'init'