diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index 0b6387ed..69c80597 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -147,6 +147,44 @@ jobs:
       - name: test
         run: yarn run test:lint
 
+  test-licenses:
+    needs: [ 'build' ]
+    name: test licenses
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: install flict
+        run: pip install flict
+      - name: Checkout
+        # see https://github.com/actions/checkout
+        uses: actions/checkout@v4
+      - name: Setup Node.js ${{ env.NODE_ACTIVE_LTS }}
+        # see https://github.com/actions/setup-node
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_ACTIVE_LTS }}
+          # cache: 'yarn'
+      - name: Setup yarn ${{ env.YARN_VERSION }}
+        run: |
+          corepack enable yarn
+          yarn set version ${{ env.YARN_VERSION }}
+      - name: Setup subject
+        run: |
+          yarn install --no-immutable
+          yarn info --name-only --recursive
+      - name: fetch build artifact
+        # see https://github.com/actions/download-artifact
+        uses: actions/download-artifact@v4
+        with:
+          name: ${{ env.BUNDLES_DIR }}
+          path: ${{ env.BUNDLES_DIR }}
+      - name: make NOTICE and summary
+        run: |
+          mkdir -p _tmp
+          yarn node tools/write-3rd-party-licenses.cjs _tmp/NOTICE _tmp/lsummary
+      - name: test license compatibility
+        run: flict display-compatibility $(cat _tmp/lsummary)
+
   test-node:
     needs: [ 'build' ]
     name: test (node${{ matrix.node-version }} ${{ matrix.os }})
diff --git a/.gitignore b/.gitignore
index 2c7bd58a..2d522963 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,7 +10,7 @@
 /dist/
 /release_assets/
 
-
+_tmp/
 
 # yarn stuff - for now, until setup is hardened
 # see also: https://yarnpkg.com/getting-started/qa#which-files-should-be-gitignored
diff --git a/tools/write-3rd-party-licenses.cjs b/tools/write-3rd-party-licenses.cjs
index 6c567478..ebf6f0be 100644
--- a/tools/write-3rd-party-licenses.cjs
+++ b/tools/write-3rd-party-licenses.cjs
@@ -74,6 +74,7 @@ async function getPackageMP (filePath, cache) {
 /**
  * @param {string} outputFile
  * @param {boolean} includeLicense
+ * @return {Promise.<Set.<string>>} used licenses
  */
 async function main (outputFile, includeLicense) {
   const metaData = JSON.parse(readFileSync(metaFile))
@@ -139,7 +140,8 @@ async function main (outputFile, includeLicense) {
     'that are compatibly licensed. We list these here.\n')
   for (const tpLicense of tpLicenses) {
     writeSync(outputFH, `\n${'-'.repeat(80)}\n`)
-    writeSync(outputFH, `Library Name: ${tpLicense.name} (${tpLicense.version})\n`)
+    writeSync(outputFH, `Name: ${tpLicense.name}\n`)
+    writeSync(outputFH, `Version: ${tpLicense.version}\n`)
     writeSync(outputFH, `Distribution: https://www.npmjs.com/package/${tpLicense.name.replaceAll('@', '%40')}/v/${tpLicense.version}\n`)
     writeSync(outputFH, `License declared: ${tpLicense.licenseDeclared}\n`)
     for (const licenseFile of tpLicense.licenseFiles) {
@@ -155,12 +157,20 @@ async function main (outputFile, includeLicense) {
   }
 
   closeSync(outputFH)
+
+  return new Set(tpLicenses.map(l => l.licenseDeclared))
 }
 
 if (require.main === module) {
   const outputFile = process.argv[2] || `${metaFile}.NOTICE`
+  const lsummaryFile = process.argv[3] || `${outputFile}.lsummary`
   const includeLicense = false
-  main(outputFile, includeLicense)
+  main(outputFile, includeLicense).then(licenses => {
+    const lsummaryFH = openSync(lsummaryFile, 'w')
+    writeSync(lsummaryFH, JSON.parse(readFileSync(join(projectRoot, 'package.json'))).license + '\n')
+    writeSync(lsummaryFH, Array.from(licenses).sort().join('\n'))
+    closeSync(lsummaryFH)
+  })
 } else {
   module.exports = main
 }