diff --git a/TestModels/CallingAWSSDKFromLocalService/Model/CallingAWSSDKFromLocalService.smithy b/TestModels/CallingAWSSDKFromLocalService/Model/CallingAWSSDKFromLocalService.smithy
index edc289517..457e4e60d 100644
--- a/TestModels/CallingAWSSDKFromLocalService/Model/CallingAWSSDKFromLocalService.smithy
+++ b/TestModels/CallingAWSSDKFromLocalService/Model/CallingAWSSDKFromLocalService.smithy
@@ -49,7 +49,6 @@ structure CallDDBScanInput {
 }
 
 structure CallDDBScanOutput {
-  @required
   itemOutput: com.amazonaws.dynamodb#Integer,
 }
 
@@ -68,7 +67,6 @@ structure CallDDBGetItemInput {
 }
 
 structure CallDDBGetItemOutput {
-  @required
   itemOutput: com.amazonaws.dynamodb#AttributeMap,
 }
 
@@ -107,7 +105,6 @@ structure CallKMSEncryptInput {
 }
 
 structure CallKMSEncryptOutput {
-  @required
   encryptOutput: com.amazonaws.kms#KeyIdType,
 }
 
@@ -126,9 +123,7 @@ structure CallKMSDecryptInput {
 }
 
 structure CallKMSDecryptOutput {
-  @required
   KeyIdType: com.amazonaws.kms#KeyIdType,
-  @required
   Plaintext: com.amazonaws.kms#PlaintextType
 }
 
diff --git a/TestModels/CallingAWSSDKFromLocalService/src/SimpleCallingawssdkfromlocalserviceImpl.dfy b/TestModels/CallingAWSSDKFromLocalService/src/SimpleCallingawssdkfromlocalserviceImpl.dfy
index ad2776655..8316fccf9 100644
--- a/TestModels/CallingAWSSDKFromLocalService/src/SimpleCallingawssdkfromlocalserviceImpl.dfy
+++ b/TestModels/CallingAWSSDKFromLocalService/src/SimpleCallingawssdkfromlocalserviceImpl.dfy
@@ -47,7 +47,7 @@ module SimpleCallingawssdkfromlocalserviceImpl refines AbstractSimpleCallingawss
     );
     var retScan := input.ddbClient.Scan(ScanInput);
     if retScan.Success? {
-      return Success(CallDDBScanOutput(itemOutput := retScan.value.Count.UnwrapOr(-1)));
+      return Success(CallDDBScanOutput(itemOutput := retScan.value.Count));
     } else {
       return Failure(ComAmazonawsDynamodb(retScan.error));
     }
@@ -62,7 +62,7 @@ module SimpleCallingawssdkfromlocalserviceImpl refines AbstractSimpleCallingawss
     var retGetItem := input.ddbClient.GetItem(GetItemInput);
     var emptyMap : Dynamodb.Types.AttributeMap := map[];
     if retGetItem.Success? {
-      return Success(CallDDBGetItemOutput(itemOutput := retGetItem.value.Item.UnwrapOr(emptyMap)));
+      return Success(CallDDBGetItemOutput(itemOutput := retGetItem.value.Item));
     } else {
       return Failure(ComAmazonawsDynamodb(retGetItem.error));
     }
@@ -95,7 +95,7 @@ module SimpleCallingawssdkfromlocalserviceImpl refines AbstractSimpleCallingawss
     );
     var retEncryptResponse := input.kmsClient.Encrypt(encryptInput);
     if retEncryptResponse.Success? {
-      return Success(CallKMSEncryptOutput(encryptOutput := retEncryptResponse.value.KeyId.UnwrapOr("DummyString")));
+      return Success(CallKMSEncryptOutput(encryptOutput := retEncryptResponse.value.KeyId));
     } else {
       return Failure(Types.ComAmazonawsKms(retEncryptResponse.error));
     }
@@ -108,9 +108,8 @@ module SimpleCallingawssdkfromlocalserviceImpl refines AbstractSimpleCallingawss
       KeyId := Wrappers.Some(input.keyId)
     );
     var retDecryptResponse := input.kmsClient.Decrypt(decryptInput);
-    var emptyPlainText : Kms.Types.PlaintextType := [ 0 ];
     if retDecryptResponse.Success? {
-      return Success(CallKMSDecryptOutput(KeyIdType := retDecryptResponse.value.KeyId.UnwrapOr("DummyString"), Plaintext := retDecryptResponse.value.Plaintext.UnwrapOr(emptyPlainText)));
+      return Success(CallKMSDecryptOutput(KeyIdType := retDecryptResponse.value.KeyId, Plaintext := retDecryptResponse.value.Plaintext));
     } else {
       return Failure(Types.ComAmazonawsKms(retDecryptResponse.error));
     }
diff --git a/TestModels/CallingAWSSDKFromLocalService/test/SimpleCallingawssdkfromlocalserviceImplTest.dfy b/TestModels/CallingAWSSDKFromLocalService/test/SimpleCallingawssdkfromlocalserviceImplTest.dfy
index f3b6a330a..57e0a4aa9 100644
--- a/TestModels/CallingAWSSDKFromLocalService/test/SimpleCallingawssdkfromlocalserviceImplTest.dfy
+++ b/TestModels/CallingAWSSDKFromLocalService/test/SimpleCallingawssdkfromlocalserviceImplTest.dfy
@@ -45,7 +45,7 @@ module SimpleCallingawssdkfromlocalserviceImplTest {
     var resSuccess := client.CallDDBScan(SimpleCallingawssdkfromlocalservice.Types.CallDDBScanInput(ddbClient := ddbClient, tableArn := TABLE_ARN_SUCCESS_CASE));
 
     expect resSuccess.Success?;
-    expect resSuccess.value.itemOutput != -1;
+    expect resSuccess.value.itemOutput.Some?;
   }
 
   method TestCallDDBScan_Failure(client: ISimpleCallingAWSSDKFromLocalServiceClient)
@@ -80,8 +80,8 @@ module SimpleCallingawssdkfromlocalserviceImplTest {
     var resSuccess := client.CallDDBGetItem(SimpleCallingawssdkfromlocalservice.Types.CallDDBGetItemInput(ddbClient := ddbClient, tableArn := TABLE_ARN_SUCCESS_CASE, key := Key2Get));
 
     expect resSuccess.Success?;
-    // expect resSuccess.value.itemOutput;
-    var output := resSuccess.value.itemOutput;
+    expect resSuccess.value.itemOutput.Some?;
+    var output := resSuccess.value.itemOutput.value;
 
     expect output.Keys == {"branch-key-id", "version", "create-time", "enc", "hierarchy-version", "status"};
     expect |output.Keys| == |output.Values|;
@@ -161,7 +161,8 @@ module SimpleCallingawssdkfromlocalserviceImplTest {
     var resSuccess := client.CallKMSEncrypt(SimpleCallingawssdkfromlocalservice.Types.CallKMSEncryptInput(kmsClient := kmsClient, keyId := KEY_ID_SUCCESS_CASE, plaintext := PLAIN_TEXT));
 
     expect resSuccess.Success?;
-    expect resSuccess.value.encryptOutput == KEY_ID_SUCCESS_CASE;
+    expect resSucess.value.encryptOutput.Some?;
+    expect resSuccess.value.encryptOutput.value == KEY_ID_SUCCESS_CASE;
   }
 
   method TestCallKMSEncrypt_Failure(client: ISimpleCallingAWSSDKFromLocalServiceClient)
@@ -214,8 +215,10 @@ module SimpleCallingawssdkfromlocalserviceImplTest {
     var resSuccess := client.CallKMSDecrypt(SimpleCallingawssdkfromlocalservice.Types.CallKMSDecryptInput(kmsClient := kmsClient, keyId := KEY_ID_SUCCESS_CASE, ciphertextBlob := workAround(CiphertextBlob)));
 
     expect resSuccess.Success?;
-    expect resSuccess.value.KeyIdType == KEY_ID_SUCCESS_CASE;
-    expect resSuccess.value.Plaintext == [ 165, 191, 67, 62 ];
+    expect resSuccess.value.KeyIdType.Some?;
+    expect resSuccess.value.Plaintext.Some?;
+    expect resSuccess.value.KeyIdType.value == KEY_ID_SUCCESS_CASE;
+    expect resSuccess.value.Plaintext.value == [ 165, 191, 67, 62 ];
   }
 
   method TestCallKMSDecrypt_Failure(client: ISimpleCallingAWSSDKFromLocalServiceClient)