diff --git a/core/java.mk b/core/java.mk
index 6798efa..61a3ad3 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -501,9 +501,9 @@
 	$(transform-classes.jar-to-dex)
 endif
 
-ifneq ($(filter $(LOCAL_MODULE),$(PRODUCT_BOOT_JARS)),)
-  $(call pretty-error,Modules in PRODUCT_BOOT_JARS must be defined in Android.bp files)
-endif
+$(foreach pair,$(PRODUCT_BOOT_JARS), \
+  $(if $(filter $(LOCAL_MODULE),$(call word-colon,2,$(pair))), \
+    $(call pretty-error,Modules in PRODUCT_BOOT_JARS must be defined in Android.bp files)))
 
 $(built_dex): $(built_dex_intermediate)
 	@echo Copying: $@