diff --git a/Makefile b/Makefile
index a03a95c..9cbb6df 100644
--- a/Makefile
+++ b/Makefile
@@ -17,7 +17,7 @@ options:
 .c.o:
 	$(CC) -c $(CFLAGS) $<
 
-config.h:
+config.h: config.def.h
 	cp config.def.h $@
 
 $(OBJ): arg.h config.h config.mk drw.h