--- old/make/CompileDemos.gmk	2017-10-05 11:55:50.352933023 +0200
+++ new/make/CompileDemos.gmk	2017-10-05 11:55:50.096937064 +0200
@@ -303,7 +303,7 @@
 
 ################################################################################
 # Hook to include the corresponding custom file, if present.
-$(eval $(call IncludeCustomExtension, , CompileDemos.gmk))
+$(eval $(call IncludeCustomExtension, CompileDemos.gmk))
 
 all: $(TARGETS)
 images: $(IMAGES_TARGETS)