diff --git a/scrapy/extension.py b/scrapy/extension.py
index 6be14450c..8221b675e 100644
--- a/scrapy/extension.py
+++ b/scrapy/extension.py
@@ -4,7 +4,10 @@ The Extension Manager
 See documentation in docs/topics/extensions.rst
 """
 
+from typing import Any, List
+
 from scrapy.middleware import MiddlewareManager
+from scrapy.settings import Settings
 from scrapy.utils.conf import build_component_list
 
 
@@ -12,5 +15,5 @@ class ExtensionManager(MiddlewareManager):
     component_name = "extension"
 
     @classmethod
-    def _get_mwlist_from_settings(cls, settings):
+    def _get_mwlist_from_settings(cls, settings: Settings) -> List[Any]:
         return build_component_list(settings.getwithbase("EXTENSIONS"))