diff --git a/docs/capabilities.md b/docs/capabilities.md
index f374205..34770ea 100644
--- a/docs/capabilities.md
+++ b/docs/capabilities.md
@@ -32,7 +32,7 @@ import { MY_KEY } from '$env/static/public';
 MY_KEY
 ```
 
-Default scanned file types: .ts, .js, jsx, tsx, vue, .mjs, .cjs, .svelte
+Default scanned file types: .ts, .js, jsx, tsx, vue, .mjs, .mts, .cjs, .cts, .svelte
 
 ## What It Checks For
 
diff --git a/src/core/scan/patterns.ts b/src/core/scan/patterns.ts
index bec9e2b..496cbe3 100644
--- a/src/core/scan/patterns.ts
+++ b/src/core/scan/patterns.ts
@@ -120,7 +120,9 @@ export const DEFAULT_INCLUDE_EXTENSIONS = [
   '.vue',
   '.svelte',
   '.mjs',
+  '.mts',
   '.cjs',
+  '.cts',
 ];
 
 // Default patterns to exclude from scans
diff --git a/test/unit/core/scan/patterns.test.ts b/test/unit/core/scan/patterns.test.ts
index ddc18d4..177e2da 100644
--- a/test/unit/core/scan/patterns.test.ts
+++ b/test/unit/core/scan/patterns.test.ts
@@ -1,5 +1,6 @@
 import { describe, it, expect } from 'vitest';
 import { scanFile } from '../../../../src/core/scan/scanFile';
+import { DEFAULT_INCLUDE_EXTENSIONS } from '../../../../src/core/scan/patterns';
 import type { ScanOptions } from '../../../../src/config/types';
 
 describe('scanFile - Pattern Detection', () => {
@@ -158,4 +159,25 @@ describe('scanFile - Pattern Detection', () => {
       });
     });
   });
+
+  describe('Default include extensions', () => {
+    it('includes .mts in default scan extensions', () => {
+      expect(DEFAULT_INCLUDE_EXTENSIONS).toContain('.mts');
+    });
+
+    it('includes .cts in default scan extensions', () => {
+      expect(DEFAULT_INCLUDE_EXTENSIONS).toContain('.cts');
+    });
+
+    it('will detect patterns in .mts files', () => {
+      const code = 'const val = process.env.MY_KEY;';
+      const result = scanFile('test.mts', code, baseOpts);
+
+      expect(result).toHaveLength(1);
+      expect(result[0]).toMatchObject({
+        variable: 'MY_KEY',
+        pattern: 'process.env',
+      });
+    });
+  });
 });