diff --git a/make/js.mk b/make/js.mk
index b526d807..d7c0b7e3 100644
--- a/make/js.mk
+++ b/make/js.mk
@@ -23,8 +23,12 @@ all: $(JS_GENERATED)
 clean: minify.clean
 
 %.min.js: %.js
+ifneq ($(JS_MINIFY_FILTER_IN),)
 	cat $< | $(JS_MINIFY_FILTER_IN) > $@.filtered
 	$(JS_MINIFY) $@.filtered > $@.tmp
+else
+	$(JS_MINIFY) $< > $@.tmp
+endif
 	mv $@.tmp $@
 
 minify.clean: