diff --git a/Makefile b/Makefile
index ad20fb5..9b55e8a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,6 @@
 all:github
 
-GITHUB_COMMIT=$(COMMIT)
+GITHUB_COMMIT := $(COMMIT)
 
 ifeq ($(GITHUB_COMMIT), )
 GITHUB_COMMIT="使用cdev_add注册字符设备--books/fengguojin/src/1drivermodel/1-3register_chrdev--http://book.51cto.com/art/201205/337667.htm"