diff -Naur Python-3.7.0-orig/Modules/_abc.c Python-3.7.0/Modules/_abc.c
--- Python-3.7.0-orig/Modules/_abc.c	2018-06-27 06:07:35.000000000 +0300
+++ Python-3.7.0/Modules/_abc.c	2018-07-12 10:22:24.099663800 +0300
@@ -66,7 +66,7 @@
 "Internal state held by ABC machinery.");
 
 static PyTypeObject _abc_data_type = {
-    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    PyVarObject_HEAD_INIT(NULL, 0)
     "_abc_data",                        /*tp_name*/
     sizeof(_abc_data),                  /*tp_size*/
     .tp_dealloc = (destructor)abc_data_dealloc,