diff --git a/Include/pymacro.h b/Include/pymacro.h
index 69577b7..3f6ddbe 100644
--- a/Include/pymacro.h
+++ b/Include/pymacro.h
@@ -95,4 +95,6 @@
 #define Py_UNUSED(name) _unused_ ## name
 #endif
 
+#define Py_UNREACHABLE() abort()
+
 #endif /* Py_PYMACRO_H */