diff --git a/radicale/app/__init__.py b/radicale/app/__init__.py
index fb2e8e82..aeb4daf2 100644
--- a/radicale/app/__init__.py
+++ b/radicale/app/__init__.py
@@ -75,7 +75,6 @@ class Application(ApplicationPartDelete, ApplicationPartHead,
     _extra_headers: Mapping[str, str]
     _permit_delete_collection: bool
     _permit_overwrite_collection: bool
-    _strict_preconditions: bool
 
     def __init__(self, configuration: config.Configuration) -> None:
         """Initialize Application.
diff --git a/radicale/app/base.py b/radicale/app/base.py
index 28b6f262..6e3a7cd3 100644
--- a/radicale/app/base.py
+++ b/radicale/app/base.py
@@ -41,6 +41,7 @@ class ApplicationBase:
     _encoding: str
     _permit_delete_collection: bool
     _permit_overwrite_collection: bool
+    _strict_preconditions: bool
     _hook: hook.BaseHook
 
     def __init__(self, configuration: config.Configuration) -> None: