diff --git a/frontend/mobile-app/lib/features/mining/presentation/pages/mining_page.dart b/frontend/mobile-app/lib/features/mining/presentation/pages/mining_page.dart
index 58e42319..11534ed3 100644
--- a/frontend/mobile-app/lib/features/mining/presentation/pages/mining_page.dart
+++ b/frontend/mobile-app/lib/features/mining/presentation/pages/mining_page.dart
@@ -69,7 +69,7 @@ class _MiningPageState extends ConsumerState<MiningPage> {
       accountService.getLocalAvatarPath(),
     ]);
 
-    final serialNum = results[0] as int?;
+    final serialNum = results[0] as String?;
     final avatarSvg = results[1] as String?;
     final avatarUrl = results[2] as String?;
     final localAvatarPath = results[3] as String?;
diff --git a/frontend/mobile-app/lib/features/profile/presentation/pages/profile_page.dart b/frontend/mobile-app/lib/features/profile/presentation/pages/profile_page.dart
index 5156d003..da2b70e7 100644
--- a/frontend/mobile-app/lib/features/profile/presentation/pages/profile_page.dart
+++ b/frontend/mobile-app/lib/features/profile/presentation/pages/profile_page.dart
@@ -165,7 +165,7 @@ class _ProfilePageState extends ConsumerState<ProfilePage> {
     ]);
 
     final username = results[0] as String?;
-    final serialNum = results[1] as int?;
+    final serialNum = results[1] as String?;
     final avatarSvg = results[2] as String?;
     final avatarUrl = results[3] as String?;
     final localAvatarPath = results[4] as String?;