diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 21d36aa6c6..6a41e5c4c1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -22,7 +22,13 @@ jobs:
             # and package-lock.json. Needs to run before npm install
             - run: node version-check.js
             - run: npm ci
-            - run: npm test
+            # Node 25 has a known incompatibility: extension-less files in "type: module"
+            # packages are treated as ESM, causing c8's require('yargs/yargs') to fail.
+            # Fall back to plain unit tests without coverage on Node 25 until upstream fixes this.
+            - if: matrix.node != '25'
+              run: npm test
+            - if: matrix.node == '25'
+              run: npm run test-no-coverage
             - run: npm run lint
             - run: npm audit --audit-level=critical
             - run: npm run build-with-tests && npm run test-transpiled
diff --git a/package.json b/package.json
index da91ce9d6b..8c470ea6ce 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
         "generate": "./generate-client.sh",
         "watch": "tsc --watch",
         "test": "c8 node --test --test-reporter=spec --import tsx src/*_test.ts",
+        "test-no-coverage": "node --test --test-reporter=spec --import tsx src/*_test.ts",
         "test-transpiled": "node --test --test-reporter=spec dist/*_test.js",
         "integration-test": "tsx src/test/integration/index.ts",
         "prepare": "npm run build && husky",