diff --git a/src/forgesync/mirror.py b/src/forgesync/mirror.py
index 8001b04..ae8fb89 100644
--- a/src/forgesync/mirror.py
+++ b/src/forgesync/mirror.py
@@ -17,7 +17,7 @@ class PushMirrorConfig:
     immediate: bool | None = None
     sync_on_commit: bool | None = None
 
-    def overlay(self, other: Self) -> Self:
+    def overlay(self: Self, other: Self) -> Self:
         result = type(self)()
         for f in fields(self):
             value = (  # pyright: ignore[reportAny]