diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bf02210ebd..d1d63d6093 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,4 +8,6 @@ on:
 jobs:
   ci:
     name: CI
+    # Do not run if this is a pull-request from same repo i.e. not a fork repo
+    if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository
     uses: silverstripe/gha-ci/.github/workflows/ci.yml@v1