Swagger schema validation failed.

[indreek]

I have a route with joy validation.
{
method: 'GET',
path : '/users/login_history/{historyLength?}',
config: {
description: 'Get login history for current user.',
notes : 'Get login history for current user.',
tags : ['api', 'get', 'user', 'history', 'login', 'current'],
handler : userController.listLoginHistory,
validate : userValidate.listLoginHistory,
response : {schema: userModel.listLoginHistory},
plugins : {
'hapi-swagger': {
responseMessages: [
{code: 400, message: 'Bad Request'},
{code: 401, message: 'Unauthorized'}
]
}
}
}

userValidate.listLoginHistory : {
params : Joi.object({historyLength: Joi.number().integer().default(5)}).meta({className: 'listLoginHistory'}),
headers: AuthSchema.headers
}

And i get error
Swagger schema validation failed.
Data does not match any schemas from 'oneOf' at #/paths//users/login_history/{historyLength}/get/parameters/0
Data does not match any schemas from 'oneOf' at #/paths//users/login_history/{historyLength}/get/parameters/0
Missing required property: schema at #/
Data does not match any schemas from 'oneOf' at #/
No enum match for: path at #/in
No enum match for: path at #/in
No enum match for: path at #/in
No enum match for: false at #/required
Missing required property: $ref at #/paths//users/login_history/{historyLength}/get/parameters/0

JSON_OBJECT_VALIDATION_FAILED
}

If i change historyLength to .required() error dissapears. How to describe optional parameter?

Thanks,
Indrek