diff --git a/flask/exthook.py b/flask/exthook.py
index 6522e063..d8842802 100644
--- a/flask/exthook.py
+++ b/flask/exthook.py
@@ -68,7 +68,7 @@ class ExtensionImporter(object):
 
         warnings.warn(
             "Importing flask.ext.{x} is deprecated, use flask_{x} instead."
-            .format(x=modname), ExtDeprecationWarning
+            .format(x=modname), ExtDeprecationWarning, stacklevel=2
         )
 
         for path in self.module_choices: