Error handling on invalid mapping data

[ppf2]

DELETE /test1
PUT /test1
PUT /test1/test/_mapping
{
  "mappings":
  {
    "test":{
      "properties":{
        "prop1":{
          "type": "string",
          "index" : "not_analyzed"
        }
      }
    }
  }
}
GET /test1/test/_mapping

The 2nd PUT request above is invalid but it is still accepted/acknowledged by the engine. Would be nice to add some validation to the above use case to return an error.