diff --git a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
index 7abf30b196..89b6a78e72 100644
--- a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/publish/github.ts
@@ -181,6 +181,7 @@ export function createPublishGithubAction(options: {
                   },
                 },
                 {
+                  additionalProperties: false,
                   properties: {
                     access: {
                       type: 'string',