diff --git a/makefile b/makefile
index 1a35b7f..213d4f9 100644
--- a/makefile
+++ b/makefile
@@ -16,4 +16,4 @@ deel2.tar.gz: box.c chart.c main.c ui.c util.c box.h chart.h util.h ui.h util.h
 	tar czf $@ $^
 
 clean:
-	rm *.o main
+	rm -f *.o main