diff --git a/first/core.mk b/first/core.mk
index d2e32fc68..b50549da3 100644
--- a/first/core.mk
+++ b/first/core.mk
@@ -3,6 +3,7 @@ define reset
 	$(eval o :=)
 	$(eval s :=)
 	$(eval cflags :=)
+	$(eval ackflags :=)
 	$(eval ldflags :=)
 	$(eval objdir :=)
 endef