diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 2f37a38fbc..fa74972886 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -1291,7 +1291,7 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 		if (keep_fd < 0) {
 			if (errno != EEXIST)
 				die_errno(_("cannot write keep file '%s'"),
-					  keep_name);
+					  keep_name ? keep_name : name);
 		} else {
 			if (keep_msg_len > 0) {
 				write_or_die(keep_fd, keep_msg, keep_msg_len);
@@ -1299,7 +1299,7 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 			}
 			if (close(keep_fd) != 0)
 				die_errno(_("cannot close written keep file '%s'"),
-				    keep_name);
+					  keep_name ? keep_name : name);
 			report = "keep";
 		}
 	}