diff --git a/docs/usage/self-hosted-configuration.md b/docs/usage/self-hosted-configuration.md
index 86c10c63deae4d..4021d45353eb11 100644
--- a/docs/usage/self-hosted-configuration.md
+++ b/docs/usage/self-hosted-configuration.md
@@ -200,6 +200,14 @@ It will also override any settings in `packageRules`.
 ## forkMode
 
 You probably have no need for this option - it is an experimental setting for the Renovate hosted GitHub App.
+If this is set to `true` then Renovate will fork the repository into the personal space of the person owning the Personal Access Token.
+
+## forkToken
+
+You probably have no need for this option - it is an experimental setting for the Renovate hosted GitHub App.
+This should be set to a Personal Access Token (GitHub only) when `forkMode` is set to `true`.
+Renovate will use this token to fork the repository into the personal space of the person owning the Personal Access Token.
+Renovate will then create branches on the fork and opens Pull Requests on the parent repository.
 
 ## gitAuthor
 
diff --git a/lib/config/definitions.ts b/lib/config/definitions.ts
index 3c77b49792aaa2..f03a692e3b37b4 100644
--- a/lib/config/definitions.ts
+++ b/lib/config/definitions.ts
@@ -340,6 +340,15 @@ const options: RenovateOptions[] = [
     default: false,
     admin: true,
   },
+  {
+    name: 'forkToken',
+    description:
+      'Will be used on GitHub when `forkMode` is set to `true` to clone the repositories.',
+    stage: 'repository',
+    type: 'string',
+    default: '',
+    admin: true,
+  },
   {
     name: 'requireConfig',
     description: 'Set to true if repositories must have a config to activate.',