Missing type id with remote execution and plain JSON

// mode=local,language=javascript,parameters=[k, v],datatype='application/json; charset=utf-8'
cache.put(k, v);
cache.get(k);

Param1: k
Value1: {ek: 'local-json-typed-key'}

Param 2: v
Value2: {ev: 'local-json-typed-value'}

org.infinispan.commons.CacheException: com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [simple type, class java.lang.Object]: missing type id property '_type'
 at [Source: (byte[])"{"ev":"local-json-typed-value"}"; line: 1, column: 31]
com.fasterxml.jackson.databind.exc.InvalidTypeIdException: Missing type id when trying to resolve subtype of [simple type, class java.lang.Object]: missing type id property '_type'
 at [Source: (byte[])"{"ev":"local-json-typed-value"}"; line: 1, column: 31]