diff --git a/fsck.c b/fsck.c
index 99c049767..7776660d5 100644
--- a/fsck.c
+++ b/fsck.c
@@ -243,7 +243,7 @@ static int fsck_tree(struct tree *item, int strict, fsck_error error_func)
 	return retval;
 }
 
-static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
+static int fsck_ident(const char **ident, struct object *obj, fsck_error error_func)
 {
 	if (**ident == '<')
 		return error_func(obj, FSCK_ERROR, "invalid author/committer line - missing space before email");
@@ -281,7 +281,7 @@ static int fsck_ident(char **ident, struct object *obj, fsck_error error_func)
 
 static int fsck_commit(struct commit *commit, fsck_error error_func)
 {
-	char *buffer = commit->buffer;
+	const char *buffer = commit->buffer;
 	unsigned char tree_sha1[20], sha1[20];
 	struct commit_graft *graft;
 	int parents = 0;