diff --git a/README.md b/README.md
index 1002eeb2..f378ba91 100644
--- a/README.md
+++ b/README.md
@@ -99,6 +99,7 @@ ReDoc makes use of the following [vendor extensions](http://swagger.io/specifica
 * [`x-logo`](docs/redoc-vendor-extensions.md#x-logo) - is used to specify API logo
 * [`x-traitTag`](docs/redoc-vendor-extensions.md#x-traitTag) - useful for handling out common things like Pagination, Rate-Limits, etc
 * [`x-code-samples`](docs/redoc-vendor-extensions.md#x-code-samples) - specify operation code samples
+* [`x-nullable`](docs/redoc-vendor-extensions.md#nullable) - mark schema param as a nullable
 
 ### `<redoc>` tag attributes
 * `spec-url` - relative or absolute url to your spec file;
diff --git a/docs/redoc-vendor-extensions.md b/docs/redoc-vendor-extensions.md
index 9f9ea251..e12ef1e5 100644
--- a/docs/redoc-vendor-extensions.md
+++ b/docs/redoc-vendor-extensions.md
@@ -106,3 +106,13 @@ yaml
 lang: JavaScript
 source: console.log('Hello World');
 ```
+
+### Schema Object vendor extensions
+Extends OpenAPI [Schema Object](http://swagger.io/specification/#schemaObject)
+#### x-code-samples
+| Field Name     |	Type	  | Description |
+| :------------- | :------: | :---------- |
+| x-nullable | boolean | marks schema as a nullable |
+
+###### Usage in ReDoc
+Schemas marked as `x-nullable` are marked in ReDoc with the label Nullable