diff -r 220b34cbd711 Lib/inspect.py
--- a/Lib/inspect.py	Sun Sep 29 18:59:27 2013 -0700
+++ b/Lib/inspect.py	Tue Oct 01 21:48:01 2013 +0100
@@ -2068,19 +2068,17 @@
         # keyword arguments
         kwargs_param = None
         for param in itertools.chain(parameters_ex, parameters):
-            if param.kind == _POSITIONAL_ONLY:
-                # This should never happen in case of a properly built
-                # Signature object (but let's have this check here
-                # to ensure correct behaviour just in case)
-                raise TypeError('{arg!r} parameter is positional only, '
-                                'but was passed as a keyword'. \
-                                format(arg=param.name))
-
             if param.kind == _VAR_KEYWORD:
                 # Memorize that we have a '**kwargs'-like parameter
                 kwargs_param = param
                 continue
 
+            if param.kind == _VAR_POSITIONAL:
+                # Named arguments don't refer to '*args'-like parameters.
+                # We only arrive here if the positional arguments ended
+                # before reaching the last parameter before *args.
+                continue
+
             param_name = param.name
             try:
                 arg_val = kwargs.pop(param_name)
@@ -2095,6 +2093,14 @@
                                     format(arg=param_name)) from None
 
             else:
+                if param.kind == _POSITIONAL_ONLY:
+                    # This should never happen in case of a properly built
+                    # Signature object (but let's have this check here
+                    # to ensure correct behaviour just in case)
+                    raise TypeError('{arg!r} parameter is positional only, '
+                                    'but was passed as a keyword'. \
+                                    format(arg=param.name))
+
                 arguments[param_name] = arg_val
 
         if kwargs:
diff -r 220b34cbd711 Lib/test/test_inspect.py
--- a/Lib/test/test_inspect.py	Sun Sep 29 18:59:27 2013 -0700
+++ b/Lib/test/test_inspect.py	Tue Oct 01 21:48:01 2013 +0100
@@ -2299,6 +2299,12 @@
         self.assertEqual(self.call(test, 1, 2, 4, 5, bar=6),
                          (1, 2, 4, 5, 6, {}))
 
+        self.assertEqual(self.call(test, 1, 2),
+                         (1, 2, 3, 42, 50, {}))
+
+        self.assertEqual(self.call(test, 1, 2, foo=4, bar=5),
+                         (1, 2, 3, 4, 5, {}))
+
         with self.assertRaisesRegex(TypeError, "parameter is positional only"):
             self.call(test, 1, 2, c_po=4)
 
@@ -2315,6 +2321,28 @@
         ba = sig.bind(1, self=2, b=3)
         self.assertEqual(ba.args, (1, 2, 3))
 
+    def test_signature_bind_vararg_name(self):
+        def test(a, *args):
+            return a, args
+        sig = inspect.signature(test)
+        with self.assertRaisesRegex(TypeError, "too many keyword arguments"):
+            sig.bind(a=0, args=1)
+
+        def test(a=0, *args):
+            return a, args
+        sig = inspect.signature(test)
+        with self.assertRaisesRegex(TypeError, "too many keyword arguments"):
+            sig.bind(a=0, args=1)
+        with self.assertRaisesRegex(TypeError, "too many keyword arguments"):
+            sig.bind(args=1)
+
+        def test(*args, **kwargs):
+            return args, kwargs
+        self.assertEqual(self.call(test, args=1), ((), {'args': 1}))
+        sig = inspect.signature(test)
+        ba = sig.bind(args=1)
+        self.assertEqual(ba.arguments, {'kwargs': {'args': 1}})
+
 
 class TestBoundArguments(unittest.TestCase):
     def test_signature_bound_arguments_unhashable(self):