diff --git a/core/base_rules.mk b/core/base_rules.mk
index e7da560..a178b55 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -622,7 +622,7 @@
 
 # Add this module name to the tag list of each specified tag.
 $(foreach tag,$(my_module_tags),\
-    $(eval ALL_MODULE_NAME_TAGS.$(tag) += $(my_register_name)))
+    $(eval ALL_MODULE_NAME_TAGS.$(tag) := $$(ALL_MODULE_NAME_TAGS.$(tag)) $(my_register_name)))
 
 ###########################################################
 ## umbrella targets used to verify builds