diff --git a/.github/workflows/size-label.yml b/.github/workflows/size-label.yml
index 1c70544..90bd95b 100644
--- a/.github/workflows/size-label.yml
+++ b/.github/workflows/size-label.yml
@@ -2,14 +2,27 @@ name: Label based on PR size
 
 on:
   pull_request:
+  pull_request_target:
+  workflow_dispatch:
 
 jobs:
   size-label:
+    permissions: write-all
     runs-on: ubuntu-latest
 
     steps:
 
       - name: size-label
+        if: >-
+          (
+            github.event_name == 'pull_request' &&
+            github.event.pull_request.head.repo.full_name == github.repository
+          ) || (
+            github.event_name == 'pull_request_target' &&
+            github.event.pull_request.head.repo.full_name != github.repository
+          ) || (
+            github.event_name == 'workflow_dispatch'
+          )
         uses: "pascalgn/size-label-action@v0.5.0"
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"