diff -r 40d4be2b7258 Python/ceval.c
--- a/Python/ceval.c	Sat Nov 23 11:24:32 2013 +0100
+++ b/Python/ceval.c	Sat Nov 23 12:25:14 2013 +0000
@@ -3875,6 +3875,10 @@
         Py_XDECREF(value);
         Py_XDECREF(orig_traceback);
     }
+    if (orig_traceback == NULL) {
+        assert(traceback == Py_None);
+        Py_DECREF(traceback);
+    }
 }
 
 static int