diff --git a/packages/aws-cdk-lib/aws-cognito/lib/user-pool.ts b/packages/aws-cdk-lib/aws-cognito/lib/user-pool.ts
index 9976384247313..929409bc44f49 100644
--- a/packages/aws-cdk-lib/aws-cognito/lib/user-pool.ts
+++ b/packages/aws-cdk-lib/aws-cognito/lib/user-pool.ts
@@ -550,7 +550,7 @@ export interface UserPoolProps {
   readonly smsRole?: IRole;
 
   /**
-   * The 'ExternalId' that Cognito service must using when assuming the `smsRole`, if the role is restricted with an 'sts:ExternalId' conditional.
+   * The 'ExternalId' that Cognito service must be using when assuming the `smsRole`, if the role is restricted with an 'sts:ExternalId' conditional.
    * Learn more about ExternalId here - https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles_create_for-user_externalid.html
    *
    * This property will be ignored if `smsRole` is not specified.