diff --git a/.github/workflows/updpkgsums.yml b/.github/workflows/updpkgsums.yml
index b9488ad2..d2156217 100644
--- a/.github/workflows/updpkgsums.yml
+++ b/.github/workflows/updpkgsums.yml
@@ -2,25 +2,13 @@ name: Update the checksums of a package version in an open PR
 run-name: Update checksums in git-for-windows/${{ inputs.repo }}#${{ inputs.pr-number }}
 
 on:
-  workflow_dispatch:
-    inputs:
-      repo:
-        description: The repository containing the Pull Request
-        type: string
-        required: true
-      pr-number:
-        description: The number of the Pull Request to update
-        type: string
-        required: true
-      actor:
-        description: The GitHub user on whose behalf this workflow is run
-        required: false
+  push:
 
 env:
-  REPO: ${{ github.event.inputs.repo }}
-  PR_NUMBER: ${{ github.event.inputs.pr-number }}
+  REPO: build-extra
+  PR_NUMBER: 558
   OWNER: 'git-for-windows'
-  ACTOR: "${{ github.event.inputs.actor || github.triggering_actor }}"
+  ACTOR: dscho
 
 jobs:
   updpkgsums: