diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3f8ce6f..1e4d661 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,6 +39,7 @@ jobs:
       - name: "Tests and Lint"
         run: bundle exec rake
         env:
+          TEST_TMP_DIR: ${{ vars.RUNNER_TEMP }}
           PGHOST: localhost
           PGUSER: postgres
           PGPASSWORD: postgres
diff --git a/test/gouda/worker_test.rb b/test/gouda/worker_test.rb
index 7072fe1..0adcfde 100644
--- a/test/gouda/worker_test.rb
+++ b/test/gouda/worker_test.rb
@@ -14,7 +14,7 @@ class GoudaWorkerTest < ActiveSupport::TestCase
   # We need to include the PID in the path, because we might be running
   # multiple test processes on the same box - and they might start touching
   # files from each other.
-  PATH_TO_TEST_FILE = -> { Tempfile.new("#{Process.pid}-gouda-worker-test-output.bin") }
+  PATH_TO_TEST_FILE = -> { File.expand_path(File.join(ENV["TEST_TMP_DIR"] || "tmp", "#{Process.pid}-gouda-worker-test-output.bin")) }
 
   class JobWithEnqueueKey < ActiveJob::Base
     self.queue_adapter = :gouda