Must terminate the Pickler_members[] and Pickler_getsets with NULL.
diff --git a/Modules/cPickle.c b/Modules/cPickle.c
index 3a98259..b2392f9 100644
--- a/Modules/cPickle.c
+++ b/Modules/cPickle.c
@@ -2461,6 +2461,7 @@
 static PyMemberDef Pickler_members[] = {
     {"binary", T_INT, offsetof(Picklerobject, bin)},
     {"fast", T_INT, offsetof(Picklerobject, fast)},
+    {NULL}
 };
 
 static PyGetSetDef Pickler_getsets[] = {
@@ -2468,7 +2469,8 @@
                      (setter)Pickler_set_pers_func},
     {"inst_persistent_id", NULL, (setter)Pickler_set_inst_pers_func},
     {"memo", (getter)Pickler_get_memo, (setter)Pickler_set_memo},
-    {"PicklingError", (getter)Pickler_get_error, NULL}
+    {"PicklingError", (getter)Pickler_get_error, NULL},
+    {NULL}
 };
 
 static char Picklertype__doc__[] =