diff --git a/csrf.py b/csrf.py
index a415163420db2baa8121ee5a10323dc6008a62e7..8608ed5ceeab90174f7e473838971d5df7641558 100644
--- a/csrf.py
+++ b/csrf.py
@@ -1,5 +1,7 @@
 from functools import wraps
 from hmac import compare_digest
+import hashlib
+import os
 
 from flask import request, abort, session