diff --git a/setup.c b/setup.c
index a0cb42c235..03efbb274a 100644
--- a/setup.c
+++ b/setup.c
@@ -797,7 +797,7 @@ static const char *setup_discovered_git_dir(const char *gitdir,
 		set_git_dir(gitdir);
 	inside_git_dir = 0;
 	inside_work_tree = 1;
-	if (offset == cwd->len)
+	if (offset >= cwd->len)
 		return NULL;
 
 	/* Make "offset" point past the '/' (already the case for root dirs) */