diff --git a/Makefile b/Makefile
index 470ac86..22cec89 100644
--- a/Makefile
+++ b/Makefile
@@ -15,7 +15,7 @@ options:
 	@echo "LDFLAGS = $(STLDFLAGS)"
 	@echo "CC      = $(CC)"
 
-config.h:
+config.h: config.def.h
 	cp config.def.h config.h
 
 .c.o: