diff --git a/core/base_rules.mk b/core/base_rules.mk
index e3f8a70..511dda5 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -748,7 +748,7 @@
 ## Register with ALL_MODULES
 ###########################################################
 
-ifeq ($(filter $(my_register_name),$(ALL_MODULES)),)
+ifndef ALL_MODULES.$(my_register_name).PATH
     # These keys are no longer used, they've been replaced by keys that specify
     # target/host/host_cross (REQUIRED_FROM_TARGET / REQUIRED_FROM_HOST) and similar.
     #