diff --git a/lib/reducers/message-reducer.js b/lib/reducers/message-reducer.js
--- a/lib/reducers/message-reducer.js
+++ b/lib/reducers/message-reducer.js
@@ -1245,25 +1245,41 @@
       (localInfo: LocalMessageInfo, key: string) => key !== payload.localID,
     )(messageStore.local);
 
+    const updatedThreads = {
+      [threadID]: {
+        ...messageStore.threads[threadID],
+        messageIDs: newMessageIDs,
+      },
+    };
+    messageStoreOperations.push({
+      type: 'replace_threads',
+      payload: { threads: { ...updatedThreads } },
+    });
+
     const processedMessageStore = processMessageStoreOperations(
       messageStore,
       messageStoreOperations,
     );
 
+    const newMessageStore = {
+      ...messageStore,
+      messages: processedMessageStore.messages,
+      threads: {
+        ...messageStore.threads,
+        ...updatedThreads,
+      },
+      local,
+    };
+
+    assertMessageStoreThreadsAreEqual(
+      processedMessageStore,
+      newMessageStore,
+      action.type,
+    );
+
     return {
       messageStoreOperations,
-      messageStore: {
-        ...messageStore,
-        messages: processedMessageStore.messages,
-        threads: {
-          ...messageStore.threads,
-          [threadID]: {
-            ...messageStore.threads[threadID],
-            messageIDs: newMessageIDs,
-          },
-        },
-        local,
-      },
+      messageStore: newMessageStore,
     };
   } else if (action.type === saveMessagesActionType) {
     const truncationStatuses = {};