diff --git a/Makefile b/Makefile
index faf08c0..dc4880b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,8 @@
 COVER_PROFILE=cover.out
 COVER_HTML=cover.html
 
+.PHONY: $(COVER_PROFILE) $(COVER_HTML)
+
 all: open
 
 build: clean