diff --git a/lib/push/send-utils.js b/lib/push/send-utils.js
--- a/lib/push/send-utils.js
+++ b/lib/push/send-utils.js
@@ -1247,8 +1247,8 @@
     devices: $ReadOnlyArray<DeviceSessionCreationRequest>,
   ) => Promise<void>,
   +auxUserInfos: AuxUserInfos,
-  +rescindData?: { threadID: string },
-  +badgeUpdateData?: { threadID: string },
+  +rescindData?: { +threadID: string },
+  +badgeUpdateData?: { +threadID: string },
 };
 
 async function prepareOwnDevicesPushNotifs(
diff --git a/lib/types/notif-types.js b/lib/types/notif-types.js
--- a/lib/types/notif-types.js
+++ b/lib/types/notif-types.js
@@ -36,9 +36,9 @@
       }>,
     }
   | {
-      +rescindData: { threadID: string },
+      +rescindData: { +threadID: string },
     }
-  | { +badgeUpdateData: { threadID: string } };
+  | { +badgeUpdateData: { +threadID: string } };
 
 export type SenderDeviceDescriptor =
   | { +keyserverID: string }