diff --git a/protos/SignalStorage.proto b/protos/SignalStorage.proto
index 0acc53fd1..f6980b0b6 100644
--- a/protos/SignalStorage.proto
+++ b/protos/SignalStorage.proto
@@ -45,8 +45,10 @@ message ManifestRecord {
     optional Type  type = 2;
   }
 
-  optional uint64     version = 1;
-  repeated Identifier keys    = 2;
+  optional uint64      version = 1;
+  optional uint32 sourceDevice = 3;
+  repeated Identifier     keys = 2;
+  // Next ID: 4
 }
 
 message StorageRecord {
diff --git a/ts/services/storage.ts b/ts/services/storage.ts
index 08c5de203..bee9e2285 100644
--- a/ts/services/storage.ts
+++ b/ts/services/storage.ts
@@ -498,6 +498,7 @@ async function generateManifest(
 
   const manifestRecord = new Proto.ManifestRecord();
   manifestRecord.version = Long.fromNumber(version);
+  manifestRecord.sourceDevice = window.storage.user.getDeviceId() ?? 0;
   manifestRecord.keys = Array.from(manifestRecordKeys);
 
   const storageKeyBase64 = window.storage.get('storageKey');
@@ -1335,7 +1336,8 @@ async function sync(
     const version = manifest.version?.toNumber() ?? 0;
 
     log.info(
-      `storageService.sync: updating to remoteVersion=${version} from ` +
+      `storageService.sync: updating to remoteVersion=${version} ` +
+        `sourceDevice=${manifest.sourceDevice ?? '?'} from ` +
         `version=${localManifestVersion}`
     );