diff --git a/flask/ctx.py b/flask/ctx.py
index a189b28f..0943d10a 100644
--- a/flask/ctx.py
+++ b/flask/ctx.py
@@ -12,7 +12,6 @@
 from werkzeug.exceptions import HTTPException
 
 from .globals import _request_ctx_stack
-from .session import _NullSession
 from .module import blueprint_is_module