diff --git a/frontend/mobile-upgrade/src/infrastructure/repositories/version-repository-impl.ts b/frontend/mobile-upgrade/src/infrastructure/repositories/version-repository-impl.ts
index 69df5d62..efcf271f 100644
--- a/frontend/mobile-upgrade/src/infrastructure/repositories/version-repository-impl.ts
+++ b/frontend/mobile-upgrade/src/infrastructure/repositories/version-repository-impl.ts
@@ -62,7 +62,8 @@ export class VersionRepositoryImpl implements IVersionRepository {
   async upload(input: UploadVersionInput): Promise<AppVersion> {
     const formData = new FormData()
     formData.append('file', input.file)
-    formData.append('platform', input.platform)
+    // Backend expects uppercase platform (ANDROID, IOS)
+    formData.append('platform', input.platform.toUpperCase())
     formData.append('versionName', input.versionName)
     formData.append('buildNumber', input.buildNumber)
     formData.append('isForceUpdate', String(input.isForceUpdate ?? false))
@@ -93,7 +94,8 @@ export class VersionRepositoryImpl implements IVersionRepository {
   async parsePackage(file: File, platform: Platform): Promise<ParsedPackageInfo> {
     const formData = new FormData()
     formData.append('file', file)
-    formData.append('platform', platform)
+    // Backend expects uppercase platform (ANDROID, IOS)
+    formData.append('platform', platform.toUpperCase())
 
     const response = await this.client.post<ParsedPackageInfo>(
       '/api/v1/versions/parse',