diff --git a/.github/workflows/sop-test-suite.yml b/.github/workflows/sop-test-suite.yml
index 6435450e..f2ca1b64 100644
--- a/.github/workflows/sop-test-suite.yml
+++ b/.github/workflows/sop-test-suite.yml
@@ -17,6 +17,10 @@ jobs:
     steps:
       # check out repo for scripts
       - uses: actions/checkout@v5
+      # the interop image does not include Node.js
+      - uses: actions/setup-node@v6
+        with:
+          node-version: '22.x'
       # check out pull request branch
       - name: Checkout openpgpjs-branch
         uses: actions/checkout@v5