diff -r d14f40c87438 Parser/asdl_c.py
--- a/Parser/asdl_c.py	Sat Jul 27 00:03:47 2013 +0200
+++ b/Parser/asdl_c.py	Sat Jul 27 00:25:42 2013 +0200
@@ -834,9 +834,13 @@ static int obj2ast_object(PyObject* obj,
 {
     if (obj == Py_None)
         obj = NULL;
-    if (obj)
-        PyArena_AddPyObject(arena, obj);
-    Py_XINCREF(obj);
+    if (obj) {
+        if (PyArena_AddPyObject(arena, obj) < 0) {
+            *out = NULL;
+            return -1;
+        }
+        Py_INCREF(obj);
+    }
     *out = obj;
     return 0;
 }
diff -r d14f40c87438 Python/Python-ast.c
--- a/Python/Python-ast.c	Sat Jul 27 00:03:47 2013 +0200
+++ b/Python/Python-ast.c	Sat Jul 27 00:25:42 2013 +0200
@@ -688,9 +688,13 @@ static int obj2ast_object(PyObject* obj,
 {
     if (obj == Py_None)
         obj = NULL;
-    if (obj)
-        PyArena_AddPyObject(arena, obj);
-    Py_XINCREF(obj);
+    if (obj) {
+        if (PyArena_AddPyObject(arena, obj) < 0) {
+            *out = NULL;
+            return -1;
+        }
+        Py_INCREF(obj);
+    }
     *out = obj;
     return 0;
 }