diff --git a/builtin/init-db.c b/builtin/init-db.c
index 944ec77..b11f070 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -378,7 +378,7 @@
 	 * config file, so this will not fail.  What we are catching
 	 * is an attempt to reinitialize new repository with an old tool.
 	 */
-	check_repository_format();
+	check_repository_format(NULL);
 
 	reinit = create_default_files(template_dir, original_git_dir);
 
diff --git a/cache.h b/cache.h
index 158d7cc..29ee02a 100644
--- a/cache.h
+++ b/cache.h
@@ -1086,8 +1086,10 @@
  * and die if it is a version we don't understand. Generally one would
  * set_git_dir() before calling this, and use it only for "are we in a valid
  * repo?".
+ *
+ * If successful and fmt is not NULL, fill fmt with data.
  */
-void check_repository_format(void);
+void check_repository_format(struct repository_format *fmt);
 
 #define MTIME_CHANGED	0x0001
 #define CTIME_CHANGED	0x0002
diff --git a/path.c b/path.c
index 88cf593..a10b62c 100644
--- a/path.c
+++ b/path.c
@@ -851,7 +851,7 @@
 
 	if (is_git_directory(".")) {
 		set_git_dir(".");
-		check_repository_format();
+		check_repository_format(NULL);
 		return path;
 	}
 
diff --git a/setup.c b/setup.c
index 4ea7a0b..af20c3d 100644
--- a/setup.c
+++ b/setup.c
@@ -1253,10 +1253,12 @@
 	return -(i & 0666);
 }
 
-void check_repository_format(void)
+void check_repository_format(struct repository_format *fmt)
 {
 	struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT;
-	check_repository_format_gently(get_git_dir(), &repo_fmt, NULL);
+	if (!fmt)
+		fmt = &repo_fmt;
+	check_repository_format_gently(get_git_dir(), fmt, NULL);
 	startup_info->have_repository = 1;
 	clear_repository_format(&repo_fmt);
 }