diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0e73cd3d7313d00cd8bf3342849659be596f3336..754151f68cc83820b3e2985d16dd8723aaac0109 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -97,7 +97,7 @@ jobs:
         run: yarn build
 
       - name: Unit tests
-        run: yarn jest --maxWorkers=2 --ci --coverage ${{ env.coverage }}
+        run: yarn jest:${{ env.NODE_VERSION }} --maxWorkers=2 --ci --coverage ${{ env.coverage }}
 
       - name: Codecov
         uses: codecov/codecov-action@f32b3a3741e1053eb607407145bc9619351dc93b # renovate: tag=v2.1.0
diff --git a/lib/logger/index.ts b/lib/logger/index.ts
index ceee032d872cf8f562da1713c4d5318642c60102..bd0b5dffc16cebe0fbcaaf480d8e1029e1edeb5b 100644
--- a/lib/logger/index.ts
+++ b/lib/logger/index.ts
@@ -13,9 +13,11 @@ let curMeta: Record<string, unknown> = {};
 
 const problems = new ProblemStream();
 
+// istanbul ignore if: not easily testable
 if (is.string(process.env.LOG_LEVEL)) {
   process.env.LOG_LEVEL = process.env.LOG_LEVEL.toLowerCase().trim();
 }
+
 validateLogLevel(process.env.LOG_LEVEL);
 const stdout: bunyan.Stream = {
   name: 'stdout',
diff --git a/package.json b/package.json
index 8b05c9ddc4337fb712115291dbad6f093abff4da..8240e11c40581a7374e452151c586d30ec76778b 100644
--- a/package.json
+++ b/package.json
@@ -22,7 +22,9 @@
     "generate": "run-s generate:*",
     "generate:imports": "node tools/generate-imports.mjs",
     "git-check": "node tools/check-git-version.mjs",
-    "jest": "cross-env LOG_LEVEL=fatal node --expose-gc --no-compilation-cache node_modules/jest/bin/jest.js --logHeapUsage",
+    "jest": "cross-env LOG_LEVEL=fatal node --expose-gc node_modules/jest/bin/jest.js --logHeapUsage",
+    "jest:14": "node --expose-gc node_modules/jest/bin/jest.js --logHeapUsage",
+    "jest:16": "node --expose-gc --no-compilation-cache node_modules/jest/bin/jest.js --logHeapUsage",
     "jest-debug": "cross-env NODE_OPTIONS=--inspect-brk yarn jest --testTimeout=100000000",
     "jest-silent": "cross-env yarn jest --reporters jest-silent-reporter",
     "lint": "run-s ls-lint eslint prettier markdown-lint git-check doc-fence-check",