diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index a498f0f..5c1a8e6 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -1646,6 +1646,7 @@
 #undef COPYNUM
 #undef COPYSEQ
 #undef COPYMAP
+#undef COPYBUF
 
 #define SLOTDEFINED(SLOT) \
 	(base->SLOT != 0 && \