diff --git a/django/models/auth.py b/django/models/auth.py
index 6c4624013d..9acb40f44f 100644
--- a/django/models/auth.py
+++ b/django/models/auth.py
@@ -213,6 +213,7 @@ class Session(meta.Model):
             raise SessionDoesNotExist
         session_md5, tamper_check = session_cookie_string[:32], session_cookie_string[32:]
         if md5.new(session_md5 + SECRET_KEY + 'auth').hexdigest() != tamper_check:
+            from django.core.exceptions import SuspiciousOperation
             raise SuspiciousOperation, "User may have tampered with session cookie."
         return get_object(session_md5__exact=session_md5, select_related=True)