diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7e78e54..39145a3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,6 +14,9 @@ on:
 
 jobs:
   xmllint:
+    # Don't run the cron job on forks.
+    if: ${{ github.event_name != 'schedule' || github.event.repository.fork == false }}
+
     name: 'Check XML'
     runs-on: ubuntu-latest
 
@@ -55,6 +58,9 @@ jobs:
           diff -B ./PHPCompatibilitySymfonyPolyfillPHP80/ruleset.xml <(xmllint --format "./PHPCompatibilitySymfonyPolyfillPHP80/ruleset.xml")
 
   test:
+    # Don't run the cron job on forks.
+    if: ${{ github.event_name != 'schedule' || github.event.repository.fork == false }}
+
     needs: xmllint
     runs-on: ubuntu-latest