diff --git a/setup.c b/setup.c
index e3781b656d..01e1a6a7c5 100644
--- a/setup.c
+++ b/setup.c
@@ -153,6 +153,8 @@ static int is_git_directory(const char *suspect)
 	char path[PATH_MAX];
 	size_t len = strlen(suspect);
 
+	if (PATH_MAX <= len + strlen("/objects"))
+		die("Too long path: %.*s", 60, suspect);
 	strcpy(path, suspect);
 	if (getenv(DB_ENVIRONMENT)) {
 		if (access(getenv(DB_ENVIRONMENT), X_OK))