diff --git a/.github/workflows/gputests.yml b/.github/workflows/gputests.yml
index bb7f51d29..66e0707e0 100644
--- a/.github/workflows/gputests.yml
+++ b/.github/workflows/gputests.yml
@@ -10,6 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         branch: [master, v4]
+    if: github.repository_owner == 'explosion'
     runs-on: ubuntu-latest
     steps:
       - name: Trigger buildkite build
diff --git a/.github/workflows/slowtests.yml b/.github/workflows/slowtests.yml
index 1a99c751c..38ceb18c6 100644
--- a/.github/workflows/slowtests.yml
+++ b/.github/workflows/slowtests.yml
@@ -10,6 +10,7 @@ jobs:
       fail-fast: false
       matrix:
         branch: [master, v4]
+    if: github.repository_owner == 'explosion'
     runs-on: ubuntu-latest
     steps:
       - name: Checkout