diff --git a/src/components/vitest.ts b/src/components/vitest.ts
index 3b16055..059a845 100755
--- a/src/components/vitest.ts
+++ b/src/components/vitest.ts
@@ -20,7 +20,13 @@ export function defaultVitestOptions(): VitestOptions {
           branches: 87,
           statements: 89,
         },
-        exclude: ['src/utils/test', '.projenrc.ts', 'src/cli', 'src/scripts'],
+        exclude: [
+          'src/utils/test',
+          '.projenrc.ts',
+          'src/cli',
+          'src/scripts',
+          'lib',
+        ],
       },
       exclude: ['.cache', '.git', '.idea', 'dist', 'lib', 'node_modules'],
       globals: true,
diff --git a/src/projects/__snapshots__/npm-package.test.ts.snap b/src/projects/__snapshots__/npm-package.test.ts.snap
index f507b33..ab8142e 100644
--- a/src/projects/__snapshots__/npm-package.test.ts.snap
+++ b/src/projects/__snapshots__/npm-package.test.ts.snap
@@ -1197,7 +1197,8 @@ export default defineConfig(
   "src/utils/test",
   ".projenrc.ts",
   "src/cli",
-  "src/scripts"
+  "src/scripts",
+  "lib"
 ]
       },
       "exclude": [
diff --git a/vitest.config.ts b/vitest.config.ts
index 443205d..353dec4 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -24,7 +24,8 @@ export default defineConfig(
   "src/utils/test",
   ".projenrc.ts",
   "src/cli",
-  "src/scripts"
+  "src/scripts",
+  "lib"
 ]
       },
       "exclude": [