diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 421a1450..b8bc5809 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -5,6 +5,7 @@ jobs:
   Build:
     name: "Build on ${{ matrix.name }}"
     runs-on: ${{ matrix.os }}
+    if: github.event_name == 'push' || github.event.pull_request.head.repo.full_name != github.repository
     strategy:
       matrix:
         include: