diff --git a/lib/shared/dm-ops/process-dm-ops.js b/lib/shared/dm-ops/process-dm-ops.js
--- a/lib/shared/dm-ops/process-dm-ops.js
+++ b/lib/shared/dm-ops/process-dm-ops.js
@@ -13,6 +13,7 @@
   createMessagesToPeersFromDMOp,
   dmOperationSpecificationTypes,
 } from './dm-op-utils.js';
+import { processNewUserIDsActionType } from '../../actions/user-actions.js';
 import { useLoggedInUserInfo } from '../../hooks/account-hooks.js';
 import { useGetLatestMessageEdit } from '../../hooks/latest-message-edit.js';
 import { useDispatchWithMetadata } from '../../hooks/ops-hooks.js';
@@ -25,6 +26,7 @@
   sendDMActionTypes,
   type SendDMOpsSuccessPayload,
 } from '../../types/dm-ops.js';
+import { dmOperationValidator } from '../../types/dm-ops.js';
 import type { LocalMessageInfo } from '../../types/message-types.js';
 import type { RawThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { DispatchMetadata } from '../../types/redux-types.js';
@@ -32,8 +34,9 @@
 import { threadTypes } from '../../types/thread-types-enum.js';
 import type { LegacyRawThreadInfo } from '../../types/thread-types.js';
 import { updateTypes } from '../../types/update-types-enum.js';
+import { extractUserIDsFromPayload } from '../../utils/conversion-utils.js';
 import { useDispatchActionPromise } from '../../utils/redux-promise-utils.js';
-import { useSelector } from '../../utils/redux-utils.js';
+import { useSelector, useDispatch } from '../../utils/redux-utils.js';
 import { messageSpecs } from '../messages/message-specs.js';
 import { updateSpecs } from '../updates/update-specs.js';
 
@@ -58,6 +61,8 @@
   const allPeerUserIDAndDeviceIDs = useSelector(getAllPeerUserIDAndDeviceIDs);
   const currentUserInfo = useSelector(state => state.currentUserInfo);
 
+  const dispatch = useDispatch();
+
   return React.useCallback(
     async (
       dmOperationSpecification: DMOperationSpecification,
@@ -153,6 +158,14 @@
         return;
       }
 
+      const newUserIDs = extractUserIDsFromPayload(dmOperationValidator, dmOp);
+      if (newUserIDs.length > 0) {
+        dispatch({
+          type: processNewUserIDsActionType,
+          payload: { userIDs: newUserIDs },
+        });
+      }
+
       const dmOpSpec = dmOpSpecs[dmOp.type];
       const notificationsCreationDataPromise = (async () => {
         return await dmOpSpec.notificationsCreationData?.(dmOp, utilities);
@@ -251,6 +264,7 @@
       allPeerUserIDAndDeviceIDs,
       currentUserInfo,
       threadInfos,
+      dispatch,
     ],
   );
 }