diff --git a/src/utils/Subscription.ts b/src/utils/Subscription.ts
index 0ea00c4fb..76290be4a 100644
--- a/src/utils/Subscription.ts
+++ b/src/utils/Subscription.ts
@@ -34,7 +34,7 @@ function createListenerCollection() {
     },
 
     get() {
-      let listeners = []
+      let listeners: Listener[] = []
       let listener = first
       while (listener) {
         listeners.push(listener)