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
@@ -435,12 +435,6 @@
         unread,
       },
     };
-    const updatedStore = {
-      threadInfos: {
-        ...state.threadInfos,
-        [threadID]: updatedThreadInfo,
-      },
-    };
     const threadStoreOperations = [
       {
         type: 'replace',
@@ -450,13 +444,12 @@
         },
       },
     ];
-    const processedStore = processThreadStoreOperations(
+    const updatedThreadStore = processThreadStoreOperations(
       state,
       threadStoreOperations,
     );
-    assertThreadStoreThreadsAreEqual(processedStore, updatedStore, action.type);
     return {
-      threadStore: updatedStore,
+      threadStore: updatedThreadStore,
       newThreadInconsistencies: [],
       threadStoreOperations,
     };