diff --git a/Makefile b/Makefile
index afdf970..87b557b 100644
--- a/Makefile
+++ b/Makefile
@@ -2,5 +2,5 @@
 
 frontend: jon/static/entry.js
 
-jon/static/entry.js: $(shell find $(SOURCEDIR) -name '*.c')
+jon/static/entry.js: $(shell find frontend -name '*.elm')
 	elm make --optimize frontend/Entry.elm --output $@