diff --git a/README.md b/README.md
index d071da3..16ca5fe 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ is ready to be reviewed.
 The `update` script is expected to be found in the origin repository
 running the PR. It is given four arguments:
 
-  * A directory in which the destination repository is checked-out
+  * A directory in which the destination repository (or a fork) is checked-out
     on the base branch
   * A file with the JSON describing the pull request in the
     destination repository
@@ -36,6 +36,9 @@ they will be pushed as a new commit in the PR.
 
 When the PR is from a forked repository, the `update` script is checked out from
 the default branch instead of the head branch of the fork.
+
+If the fork of the destination repository is specified and it does
+not exist, it is created.
 <!-- action-docs-description -->
 <!-- action-docs-inputs -->
 ## Inputs
@@ -48,6 +51,7 @@ the default branch instead of the head branch of the fork.
 | origin-pr | number of the PR in {orign-repo} | `true` |  |
 | destination-url | URL of the Forgejo instance where the cascading PR is created or updated (e.g. https://code.forgejo.org) | `true` |  |
 | destination-repo | the repository in which the cascading PR is created or updated | `true` |  |
+| destination-fork-repo | the fork of {desitnation-repo} in which the {destination-branch} will be created or updated | `false` |  |
 | destination-branch | the base branch of the destination repository for the cascading PR | `true` |  |
 | destination-token | a token with write permission on destination-repo | `true` |  |
 | update | path to the script to update the content of the cascading PR | `true` |  |