diff --git a/README.md b/README.md
index 7bc1dcaeb..5ddefa134 100644
--- a/README.md
+++ b/README.md
@@ -1011,7 +1011,7 @@ Keyword definition is an object with the following properties:
 - _valid_: pass `true`/`false` to pre-define validation result, the result returned from validation function will be ignored. This option cannot be used with macro keywords.
 - _$data_: an optional `true` value to support [$data reference](#data-reference) as the value of custom keyword. The reference will be resolved at validation time. If the keyword has meta-schema it would be extended to allow $data and it will be used to validate the resolved value. Supporting $data reference requires that keyword has validating function (as the only option or in addition to compile, macro or inline function).
 - _async_: an optional `true` value if the validation function is asynchronous (whether it is compiled or passed in _validate_ property); in this case it should return a promise that resolves with a value `true` or `false`. This option is ignored in case of "macro" and "inline" keywords.
-- _errors_: an optional boolean indicating whether keyword returns errors. If this property is not set Ajv will determine if the errors were set in case of failed validation.
+- _errors_: an optional boolean or string `"full"` indicating whether keyword returns errors. If this property is not set Ajv will determine if the errors were set in case of failed validation.
 
 _compile_, _macro_ and _inline_ are mutually exclusive, only one should be used at a time. _validate_ can be used separately or in addition to them to support $data reference.
 
diff --git a/lib/keyword.js b/lib/keyword.js
index 44d3fec56..53d95c69d 100644
--- a/lib/keyword.js
+++ b/lib/keyword.js
@@ -34,7 +34,12 @@ var definitionSchema = {
     valid: {type: 'boolean'},
     $data: {type: 'boolean'},
     async: {type: 'boolean'},
-    errors: {type: 'boolean'}
+    errors: {
+      anyOf: [
+        {type: 'boolean'},
+        {const: 'full'}
+      ]
+    }
   }
 };