better clean target
diff --git a/build/exe.mk b/build/exe.mk
index 99af7d5..c931bfd 100644
--- a/build/exe.mk
+++ b/build/exe.mk
@@ -84,7 +84,7 @@
 
 .PHONY : clean
 clean :
-	-rm -f *.o $(OBJPATH)/*/bin/$(PROGRAM_NAME)
+	-rm -f $(DEBUG_OBJS) $(RELEASE_OBJS) $(OBJPATH)/*/bin/$(PROGRAM_NAME)
 
 .PHONY : depend
 depend: