diff --git a/.github/workflows/ci-additional.yaml b/.github/workflows/ci-additional.yaml
index 2be3577d883..b476c224df6 100644
--- a/.github/workflows/ci-additional.yaml
+++ b/.github/workflows/ci-additional.yaml
@@ -16,6 +16,9 @@ jobs:
   detect-ci-trigger:
     name: detect ci trigger
     runs-on: ubuntu-latest
+    if: |
+      github.repository == 'pydata/xarray'
+      && (github.event_name == 'push' || github.event_name == 'pull_request')
     outputs:
       triggered: ${{ steps.detect-trigger.outputs.trigger-found }}
     steps:
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c11842bbb04..4f6cbbc3871 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -16,6 +16,9 @@ jobs:
   detect-ci-trigger:
     name: detect ci trigger
     runs-on: ubuntu-latest
+    if: |
+      github.repository == 'pydata/xarray'
+      && (github.event_name == 'push' || github.event_name == 'pull_request')
     outputs:
       triggered: ${{ steps.detect-trigger.outputs.trigger-found }}
     steps: