diff --git a/core/product.mk b/core/product.mk
index b001ca2..d9e4186 100644
--- a/core/product.mk
+++ b/core/product.mk
@@ -272,3 +272,7 @@
     $(eval $(error The following variables have been changed: $(changed_variables))),)
 )
 endef
+
+define add-to-product-copy-files-if-exists
+$(if $(wildcard $(word 1,$(subst :, ,$(1)))),$(1))
+endef