diff --git a/README.md b/README.md
index e582a89..eef5c1e 100644
--- a/README.md
+++ b/README.md
@@ -87,7 +87,7 @@ not exist, it is created.
 | 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` |  |
-| prefix | prefix of the cascading PR created on destination-repo (default to {origin-repo}) | `false` |  |
+| prefix | prefix of the branch from which the cascading PR is created on {destination-repo} or {destination-fork-repo} (default to {origin-repo}) | `false` |  |
 | close-merge | if true the cascading PR will be closed and the branch deleted when the PR is merged | `false` | false |
 | verbose | if true print verbose information | `false` | false |
 | debug | if true print debug information | `false` | false |
diff --git a/action.yml b/action.yml
index 8d64419..7897e12 100644
--- a/action.yml
+++ b/action.yml
@@ -102,7 +102,7 @@ inputs:
     description: 'path to the script to update the content of the cascading PR'
     required: true
   prefix:
-    description: 'prefix of the cascading PR created on destination-repo (default to {origin-repo})'
+    description: 'prefix of the branch from which the cascading PR is created on {destination-repo} or {destination-fork-repo} (default to {origin-repo})'
   close-merge:
     description: 'if true the cascading PR will be closed and the branch deleted when the PR is merged'
     default: false