#2662·ajv

removeAdditional does not work when additionalProperties is not explicitly false

Author: preederCreated Aug 10, 2026Updated Aug 10, 2026

Labelsbug report

What version of Ajv are you using? Does the issue happen if you use the latest version? 8.20.0

Ajv options object

javascript

{ removeAdditional: true }

JSON Schema

json

{
  type: 'object',
  additionalProperties: {
    not: true
  },
  properties: {
    validProp: {
      type: 'number'
    }
  }
}

Sample data { validProp: 1, invalidProp: 2 }

json

Your code

javascript

const ajv = new Ajv(options);
const validator = ajv.compile(schema);
const result = validator(data);
console.info('result: ', result);
console.info('data: ', data);
if (!result){
  console.info('Errors: ', validator.errors);
}

Validation result, data AFTER validation, error messages

result:  false
data:  { validProp: 1, invalidProp: 2 }
Errors:  [
  {
    instancePath: '/invalidProp',
    schemaPath: '#/additionalProperties/not',
    keyword: 'not',
    params: {},
    message: 'must NOT be valid'
  }
]

What results did you expect? I expected validation to pass and 'invalidProp' to be removed from data.

Are you going to resolve the issue? Yes

Source: ajv-validator/ajv

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