diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index a89ae831dd6251d7332e06470273d30fd9cb31eb..89a1f12d615bb997bd992abba61da712def3ea44 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -880,29 +880,15 @@ int cmd_index_pack(int argc, const char **argv, const char *prefix)
 	char *index_name_buf = NULL, *keep_name_buf = NULL;
 	struct pack_idx_entry **idx_objects;
 	unsigned char pack_sha1[20];
+	int nongit;
 
 	if (argc == 2 && !strcmp(argv[1], "-h"))
 		usage(index_pack_usage);
 
-	/*
-	 * We wish to read the repository's config file if any, and
-	 * for that it is necessary to call setup_git_directory_gently().
-	 * However if the cwd was inside .git/objects/pack/ then we need
-	 * to go back there or all the pack name arguments will be wrong.
-	 * And in that case we cannot rely on any prefix returned by
-	 * setup_git_directory_gently() either.
-	 */
-	{
-		char cwd[PATH_MAX+1];
-		int nongit;
-
-		if (!getcwd(cwd, sizeof(cwd)-1))
-			die("Unable to get current working directory");
-		setup_git_directory_gently(&nongit);
-		git_config(git_index_pack_config, NULL);
-		if (chdir(cwd))
-			die("Cannot come back to cwd");
-	}
+	prefix = setup_git_directory_gently(&nongit);
+	git_config(git_index_pack_config, NULL);
+	if (prefix && chdir(prefix))
+		die("Cannot come back to cwd");
 
 	for (i = 1; i < argc; i++) {
 		const char *arg = argv[i];