Bean validation not working

[krisraich]

Hello

It seems that server side bean validation is ignored.
YML Schema:

    UserCredentials:
      type: object
      required:
        - userName
        - password
      properties:
        userName:
          type: string
        password:
          type: string

Beans

    /**
     * 
     * (Required)
     * 
     */
    @JsonProperty("userName")
    private String userName;
    /**
     * 
     * (Required)
     * 
     */
    @JsonProperty("password")
    private String password;

A request that is missing a parameter should yield HTTP Code 400

Is there a configuration or package that I have overlooked?