diff --git a/package-lock.json b/package-lock.json
index 99f509b04..25ef83e12 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -28,7 +28,7 @@
         "@types/yargs": "^17.0.33",
         "@typescript-eslint/eslint-plugin": "^8.43.0",
         "@typescript-eslint/parser": "^8.43.0",
-        "chrome-devtools-frontend": "1.0.1613625",
+        "chrome-devtools-frontend": "1.0.1618066",
         "core-js": "3.49.0",
         "debug": "4.4.3",
         "eslint": "^9.35.0",
@@ -3462,9 +3462,9 @@
       }
     },
     "node_modules/chrome-devtools-frontend": {
-      "version": "1.0.1613625",
-      "resolved": "https://registry.npmjs.org/chrome-devtools-frontend/-/chrome-devtools-frontend-1.0.1613625.tgz",
-      "integrity": "sha512-Ao1y2Nq6A2XWJPEX00encO/uzt7dssmAAz5EViySpC/8bqoKM6CDNQdM1U++Gh7+qOXGM9DIMU31BQK47Krd5A==",
+      "version": "1.0.1618066",
+      "resolved": "https://registry.npmjs.org/chrome-devtools-frontend/-/chrome-devtools-frontend-1.0.1618066.tgz",
+      "integrity": "sha512-lAIWZrzt2BhGyYvsxLjslp9W85cF8X3XefPG2C31K4QICTsaiTNftmnFqixSWm0ywtutJVqBvVQUJqzABck1Bg==",
       "dev": true,
       "license": "BSD-3-Clause"
     },
diff --git a/package.json b/package.json
index 976a93d0f..f753844a9 100644
--- a/package.json
+++ b/package.json
@@ -63,7 +63,7 @@
     "@types/yargs": "^17.0.33",
     "@typescript-eslint/eslint-plugin": "^8.43.0",
     "@typescript-eslint/parser": "^8.43.0",
-    "chrome-devtools-frontend": "1.0.1613625",
+    "chrome-devtools-frontend": "1.0.1618066",
     "core-js": "3.49.0",
     "debug": "4.4.3",
     "eslint": "^9.35.0",
diff --git a/scripts/post-build.ts b/scripts/post-build.ts
index 7cf9da6ae..b40837f67 100644
--- a/scripts/post-build.ts
+++ b/scripts/post-build.ts
@@ -52,7 +52,12 @@ export const LOCAL_FETCH_PATTERN = './locales/@LOCALE@.json';`;
   );
   fs.mkdirSync(codeMirrorDir, {recursive: true});
   const codeMirrorFile = path.join(codeMirrorDir, 'codemirror.next.js');
-  const codeMirrorContent = `export default {}`;
+  const codeMirrorContent = `
+export default {};
+export const cssStreamParser = () => Promise.resolve({ startState: () => ({}) });
+export class StringStream { constructor() {} }
+export const css = { cssLanguage: { parser: { parse: () => ({ topNode: { getChild: () => null } }) } } };
+`;
   writeFile(codeMirrorFile, codeMirrorContent);
 
   // Create root mock
@@ -61,7 +66,13 @@ export const LOCAL_FETCH_PATTERN = './locales/@LOCALE@.json';`;
   const runtimeFile = path.join(rootDir, 'Runtime.js');
   const runtimeContent = `
 export function getChromeVersion() { return ''; };
+export function getRemoteBase() { return null; };
 export const hostConfig = {};
+export const GdpProfilesEnterprisePolicyValue = {
+  ENABLED: 0,
+  ENABLED_WITHOUT_BADGES: 1,
+  DISABLED: 2,
+};
 export const Runtime = {
   isDescriptorEnabled: () => true,
   queryParam: () => null,
@@ -94,6 +105,33 @@ export const ExperimentName = {
   `;
   writeFile(runtimeFile, runtimeContent);
 
+  // Copy missing CodeMirror .mjs files that tsc ignores due to .d.mts renames
+  const codemirrorDir = path.join(
+    BUILD_DIR,
+    devtoolsThirdPartyPath,
+    'codemirror',
+  );
+  const codemirrorSrcDir = path.join(
+    process.cwd(),
+    'node_modules',
+    'chrome-devtools-frontend',
+    'front_end',
+    'third_party',
+    'codemirror',
+  );
+  const filesToCopy = [
+    'package/addon/runmode/runmode-standalone.mjs',
+    'package/mode/css/css.mjs',
+    'package/mode/javascript/javascript.mjs',
+    'package/mode/xml/xml.mjs',
+  ];
+  for (const file of filesToCopy) {
+    const src = path.join(codemirrorSrcDir, file);
+    const dest = path.join(codemirrorDir, file);
+    fs.mkdirSync(path.dirname(dest), {recursive: true});
+    fs.copyFileSync(src, dest);
+  }
+
   copyDevToolsDescriptionFiles();
 }