diff --git a/types/aws-lambda/aws-lambda-tests.ts b/types/aws-lambda/aws-lambda-tests.ts
index e3356cae42..55a3d6b99f 100644
--- a/types/aws-lambda/aws-lambda-tests.ts
+++ b/types/aws-lambda/aws-lambda-tests.ts
@@ -188,6 +188,7 @@ str = cognitoUserPoolEvent.callerContext.clientId;
 str = cognitoUserPoolEvent.request.userAttributes["email"];
 str = cognitoUserPoolEvent.request.validationData["k1"];
 str = cognitoUserPoolEvent.request.codeParameter;
+str = cognitoUserPoolEvent.request.usernameParameter;
 b = cognitoUserPoolEvent.request.newDeviceUsed;
 cognitoUserPoolEvent.request.session[0].challengeName === "CUSTOM_CHALLENGE";
 cognitoUserPoolEvent.request.session[0].challengeName === "PASSWORD_VERIFIER";
diff --git a/types/aws-lambda/index.d.ts b/types/aws-lambda/index.d.ts
index 2af4e09ae7..ca84cd350d 100644
--- a/types/aws-lambda/index.d.ts
+++ b/types/aws-lambda/index.d.ts
@@ -142,6 +142,7 @@ interface CognitoUserPoolEvent {
         userAttributes: {[key: string]: string};
         validationData?: {[key: string]: string};
         codeParameter?: string;
+        usernameParameter?: string;
         newDeviceUsed?: boolean;
         session?: {
             challengeName: "CUSTOM_CHALLENGE" | "PASSWORD_VERIFIER" | "SMS_MFA" | "DEVICE_SRP_AUTH" | "DEVICE_PASSWORD_VERIFIER" | "ADMIN_NO_SRP_AUTH";