diff --git a/Bitkit.xcodeproj/project.pbxproj b/Bitkit.xcodeproj/project.pbxproj
index a1a39b9a..5764cba3 100644
--- a/Bitkit.xcodeproj/project.pbxproj
+++ b/Bitkit.xcodeproj/project.pbxproj
@@ -1201,7 +1201,7 @@
 			repositoryURL = "https://github.com/synonymdev/bitkit-core";
 			requirement = {
 				kind = exactVersion;
-				version = 0.3.9;
+				version = 0.4.0;
 			};
 		};
 		96E20CD22CB6D91A00C24149 /* XCRemoteSwiftPackageReference "CodeScanner" */ = {
diff --git a/Bitkit.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved b/Bitkit.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
index a418ff0d..3d786848 100644
--- a/Bitkit.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
+++ b/Bitkit.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved
@@ -6,8 +6,8 @@
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/synonymdev/bitkit-core",
       "state" : {
-        "revision" : "5e08294bc5701d8b48337745990a417841d6e026",
-        "version" : "0.3.9"
+        "revision" : "4979f4d23aaaeec11a09b77c8117a0afdaad4317",
+        "version" : "0.4.0"
       }
     },
     {
diff --git a/Bitkit/Services/BackupService.swift b/Bitkit/Services/BackupService.swift
index 5a8c0c38..a82138fd 100644
--- a/Bitkit/Services/BackupService.swift
+++ b/Bitkit/Services/BackupService.swift
@@ -211,7 +211,11 @@ class BackupService {
             }
 
             try await performRestore(category: .activity) { dataBytes in
-                let payload = try JSONDecoder().decode(ActivityBackupV1.self, from: dataBytes)
+                let migrated = try self.migrateCoreOwnedBackupFields(dataBytes, fieldMigrations: [
+                    "activities": migrateBackupActivitiesJson,
+                    "activityTags": migrateBackupActivityTagsJson,
+                ])
+                let payload = try JSONDecoder().decode(ActivityBackupV1.self, from: migrated)
 
                 try await CoreService.shared.activity.upsertList(payload.activities)
                 try await CoreService.shared.activity.upsertTags(payload.activityTags)
@@ -224,7 +228,10 @@ class BackupService {
             }
 
             try await performRestore(category: .metadata) { dataBytes in
-                let payload = try JSONDecoder().decode(MetadataBackupV1.self, from: dataBytes)
+                let migrated = try self.migrateCoreOwnedBackupFields(dataBytes, fieldMigrations: [
+                    "tagMetadata": migrateBackupPreActivityMetadataJson,
+                ])
+                let payload = try JSONDecoder().decode(MetadataBackupV1.self, from: migrated)
 
                 try await CoreService.shared.activity.upsertPreActivityMetadata(payload.tagMetadata)
 
@@ -739,6 +746,28 @@ class BackupService {
         }
     }
 
+    /// Fills in wallet ids that predate wallet-scoped activity data before a
+    /// backup envelope is decoded. Each Core-owned array field is handed to the
+    /// matching Core migration helper as raw JSON, so the app never edits Core
+    /// model JSON itself. Records that already carry a wallet id are left
+    /// unchanged, so this is safe to run on current backups too.
+    private func migrateCoreOwnedBackupFields(
+        _ dataBytes: Data,
+        fieldMigrations: [String: (String) throws -> String]
+    ) throws -> Data {
+        guard var root = try JSONSerialization.jsonObject(with: dataBytes) as? [String: Any] else {
+            return dataBytes
+        }
+        for (field, migrate) in fieldMigrations {
+            guard let array = root[field] as? [Any] else { continue }
+            let arrayData = try JSONSerialization.data(withJSONObject: array)
+            let migratedJson = try migrate(String(decoding: arrayData, as: UTF8.self))
+            guard let migratedData = migratedJson.data(using: .utf8) else { continue }
+            root[field] = try JSONSerialization.jsonObject(with: migratedData)
+        }
+        return try JSONSerialization.data(withJSONObject: root)
+    }
+
     private func performRestore(category: BackupCategory, restoreAction: (Data) async throws -> Void) async throws {
         do {
             let item = try await vssBackupClient.getObject(key: category.rawValue)