fix type annotation

reactive-python · Sep 4, 2020 · 49bb80f · 49bb80f
1 parent 26e3d25
commit 49bb80f
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/idom/core/hooks.py b/idom/core/hooks.py
@@ -125,7 +125,7 @@ def use_effect(
     """
     hook = current_hook()
     memoize = use_memo(args=args)
-    last_clean_callback = use_ref(None)
+    last_clean_callback: Ref[Optional[_EffectCleanFunc]] = use_ref(None)
 
     def add_effect(function: _EffectApplyFunc) -> None: