diff --git a/lib/shared/dm-ops/dm-op-utils.js b/lib/shared/dm-ops/dm-op-utils.js
--- a/lib/shared/dm-ops/dm-op-utils.js
+++ b/lib/shared/dm-ops/dm-op-utils.js
@@ -341,6 +341,8 @@
       const existingThreadDetails =
         getCreateThickRawThreadInfoInputFromThreadInfo(rawThreadInfo);
 
+      const messageID = uuid.v4();
+
       invariant(viewerID, 'viewerID should be set');
       const addViewerToThreadMembersOperation: DMAddViewerToThreadMembersOperation =
         {
@@ -348,7 +350,7 @@
           existingThreadDetails,
           editorID: viewerID,
           time: Date.now(),
-          messageID: uuid.v4(),
+          messageID,
           addedUserIDs: newMemberIDs,
         };
       const viewerOperationSpecification: OutboundDMOperationSpecification = {
@@ -367,7 +369,7 @@
         threadID: threadInfo.id,
         editorID: viewerID,
         time: Date.now(),
-        messageID: uuid.v4(),
+        messageID,
         addedUserIDs: newMemberIDs,
       };
       const newMemberIDsSet = new Set<string>(newMemberIDs);