1 files changed, 1 insertions, 1 deletions
diff --git a/tag.c b/tag.c
index 26494ca969..4041af2572 100644
--- a/tag.c
+++ b/tag.c
@@ -3,7 +3,7 @@
 
 const char *tag_type = "tag";
 
-struct tag *lookup_tag(unsigned char *sha1)
+struct tag *lookup_tag(const unsigned char *sha1)
 {
         struct object *obj = lookup_object(sha1);
         if (!obj) {