diff --git a/src/browser/extension/inject/pageScript.js b/src/browser/extension/inject/pageScript.js
index <HASH>..<HASH> 100644
--- a/src/browser/extension/inject/pageScript.js
+++ b/src/browser/extension/inject/pageScript.js
@@ -185,9 +185,11 @@ const preEnhancer = instanceId => next =>
     const store = next(reducer, preloadedState, enhancer);
 
     // Mutate the store in order to keep the reference
-    stores[instanceId].dispatch = store.dispatch;
-    stores[instanceId].liftedStore = store.liftedStore;
-    stores[instanceId].getState = store.getState;
+    if (stores[instanceId]) {
+      stores[instanceId].dispatch = store.dispatch;
+      stores[instanceId].liftedStore = store.liftedStore;
+      stores[instanceId].getState = store.getState;
+    }
 
     return {
       ...store,
Don't update the store when the page is blacklisted in settings