diff --git a/lib/reducers/thread-reducer.js b/lib/reducers/thread-reducer.js
--- a/lib/reducers/thread-reducer.js
+++ b/lib/reducers/thread-reducer.js
@@ -410,9 +410,6 @@
         threadStoreOperations: [],
       };
     }
-    const updatedStore = {
-      threadInfos: { ...state.threadInfos, ...updatedThreadInfos },
-    };
     const threadStoreOperations = Object.keys(updatedThreadInfos).map(id => ({
       type: 'replace',
       payload: {
@@ -420,13 +417,12 @@
         threadInfo: updatedThreadInfos[id],
       },
     }));
-    const processedStore = processThreadStoreOperations(
+    const updatedThreadStore = processThreadStoreOperations(
       state,
       threadStoreOperations,
     );
-    assertThreadStoreThreadsAreEqual(processedStore, updatedStore, action.type);
     return {
-      threadStore: updatedStore,
+      threadStore: updatedThreadStore,
       newThreadInconsistencies: [],
       threadStoreOperations,
     };