diff --git a/src/handlers/sync.ts b/src/handlers/sync.ts
index f013e35..d6a8f8f 100644
--- a/src/handlers/sync.ts
+++ b/src/handlers/sync.ts
@@ -112,16 +112,18 @@ export async function handleSync(request: Request, env: Env, userId: string): Pr
     },
     policies: [],
     sends: [],
-    userDecryption: {
-      masterPasswordUnlock: {
-        salt: user.email,
-        kdf: {
-          kdfType: user.kdfType,
-          iterations: user.kdfIterations,
-          memory: user.kdfMemory || null,
-          parallelism: user.kdfParallelism || null,
+    UserDecryptionOptions: {
+      HasMasterPassword: true,
+      Object: 'userDecryptionOptions',
+      MasterPasswordUnlock: {
+        Kdf: {
+          KdfType: user.kdfType,
+          Iterations: user.kdfIterations,
+          Memory: user.kdfMemory || null,
+          Parallelism: user.kdfParallelism || null,
         },
-        masterKeyEncryptedUserKey: user.key,
+        MasterKeyEncryptedUserKey: user.key,
+        Salt: user.email,
       },
     },
     object: 'sync',
diff --git a/src/types/index.ts b/src/types/index.ts
index f819372..46c10b9 100644
--- a/src/types/index.ts
+++ b/src/types/index.ts
@@ -273,6 +273,6 @@ export interface SyncResponse {
   domains: any;
   policies: any[];
   sends: any[];
-  userDecryption: any | null;
+  UserDecryptionOptions: UserDecryptionOptions | null;
   object: string;
 }