diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a5f1663..10e061d8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 0.81.1
+
+- Duplicate .d.ts files into cjs
+
+
 ## 0.80.1
 
 - Typescript 5.5.4
diff --git a/package.json b/package.json
index 7bc7ab85..0d25e176 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
   },
   "sideEffects": false,
   "type": "module",
-  "version": "0.80.1",
+  "version": "0.81.0",
   "versions": {
     "git": "0.80.1",
     "npm": "0.80.1"
diff --git a/packages/dev-test/package.json b/packages/dev-test/package.json
index 55d6248a..46a58da2 100644
--- a/packages/dev-test/package.json
+++ b/packages/dev-test/package.json
@@ -15,7 +15,7 @@
   },
   "sideEffects": false,
   "type": "module",
-  "version": "0.80.1",
+  "version": "0.81.0",
   "main": "./index.js",
   "exports": {
     "./globals.d.ts": "./src/globals.d.ts"
diff --git a/packages/dev-ts/package.json b/packages/dev-ts/package.json
index 0ba8f572..f341033d 100644
--- a/packages/dev-ts/package.json
+++ b/packages/dev-ts/package.json
@@ -15,7 +15,7 @@
   },
   "sideEffects": false,
   "type": "module",
-  "version": "0.80.1",
+  "version": "0.81.0",
   "main": "./index.js",
   "exports": {
     "./globals.d.ts": "./src/globals.d.ts"
diff --git a/packages/dev/package.json b/packages/dev/package.json
index 15685758..073522a3 100644
--- a/packages/dev/package.json
+++ b/packages/dev/package.json
@@ -15,7 +15,7 @@
   },
   "sideEffects": false,
   "type": "module",
-  "version": "0.80.1",
+  "version": "0.81.0",
   "bin": {
     "polkadot-ci-ghact-build": "./scripts/polkadot-ci-ghact-build.mjs",
     "polkadot-ci-ghact-docs": "./scripts/polkadot-ci-ghact-docs.mjs",
@@ -50,8 +50,8 @@
   },
   "dependencies": {
     "@eslint/js": "^8.56.0",
-    "@polkadot/dev-test": "^0.80.1",
-    "@polkadot/dev-ts": "^0.80.1",
+    "@polkadot/dev-test": "^0.81.0",
+    "@polkadot/dev-ts": "^0.81.0",
     "@rollup/plugin-alias": "^5.1.0",
     "@rollup/plugin-commonjs": "^25.0.7",
     "@rollup/plugin-dynamic-import-vars": "^2.1.2",
diff --git a/packages/dev/scripts/polkadot-dev-build-ts.mjs b/packages/dev/scripts/polkadot-dev-build-ts.mjs
index fc86ee8e..7a6e0f50 100755
--- a/packages/dev/scripts/polkadot-dev-build-ts.mjs
+++ b/packages/dev/scripts/polkadot-dev-build-ts.mjs
@@ -438,10 +438,12 @@ function relativePath (value) {
 function createMapEntry (rootDir, jsPath = '', noTypes) {
   jsPath = relativePath(jsPath);
 
+  const typesPath = jsPath.replace('.js', '.d.ts');
   const cjsPath = jsPath.replace('./', './cjs/');
+  const cjsTypesPath = typesPath.replace('./', './cjs/');
   const hasCjs = fs.existsSync(path.join(rootDir, cjsPath));
-  const typesPath = jsPath.replace('.js', '.d.ts');
-  const hasTypes = !noTypes && jsPath.endsWith('.js') && fs.existsSync(path.join(rootDir, typesPath));
+  const hasTypesCjs = fs.existsSync(path.join(rootDir, cjsTypesPath));
+  const hasTypes = !hasTypesCjs && !noTypes && jsPath.endsWith('.js') && fs.existsSync(path.join(rootDir, typesPath));
   const field = hasCjs
     ? {
       // As per TS, the types key needs to be first
@@ -453,12 +455,21 @@ function createMapEntry (rootDir, jsPath = '', noTypes) {
       // bundler-specific path, eg. webpack & rollup
       ...(
         jsPath.endsWith('.js')
-          ? { module: jsPath }
+          ? hasTypesCjs
+          // eslint-disable-next-line sort-keys
+            ? { module: { types: typesPath, default: jsPath } }
+            : { module: jsPath }
           : {}
       ),
-      require: cjsPath,
+      require: hasTypesCjs
+      // eslint-disable-next-line sort-keys
+        ? { types: cjsTypesPath, default: cjsPath }
+        : cjsPath,
+      // eslint-disable-next-line sort-keys
+      default: hasTypesCjs
       // eslint-disable-next-line sort-keys
-      default: jsPath
+        ? { types: typesPath, default: jsPath }
+        : jsPath
     }
     : hasTypes
       ? {
@@ -496,7 +507,10 @@ function copyBuildFiles (compileType, dir) {
   copyDirSync('src', 'build', ['.patch', '.js', '.cjs', '.mjs', '.json', '.d.ts', '.d.cts', '.d.mts', '.css', '.gif', '.hbs', '.md', '.jpg', '.png', '.rs', '.svg']);
 
   // copy all *.d.ts files
-  copyDirSync([path.join('../../build', dir, 'src'), path.join('../../build/packages', dir, 'src')], 'build', ['.d.ts']);
+  const dtsPaths = ['build-tsc', path.join('../../build', dir, 'src'), path.join('../../build/packages', dir, 'src')];
+
+  copyDirSync(dtsPaths, 'build', ['.d.ts']);
+  copyDirSync(dtsPaths, 'build/cjs', ['.d.ts']);
 
   // copy all from build-{babel|swc|tsc|...}-esm to build
   copyDirSync(`build-${compileType}-esm`, 'build');
@@ -787,6 +801,8 @@ function buildExports () {
 
   pkg.exports = listRoot
     .filter(([path, config]) =>
+      // skip d.ts files
+      !path.endsWith('.d.ts') &&
       // we handle the CJS path at the root below
       path !== './cjs/package.json' &&
       // we don't export ./deno/* paths (e.g. wasm)
@@ -1255,6 +1271,11 @@ async function buildJs (compileType, repoPath, dir, locals) {
 
   orderPackageJson(repoPath, dir, pkgJson);
 
+  // move the tsc-generated *.d.ts build files to build-tsc
+  if (fs.existsSync('build')) {
+    copyDirSync('build', 'build-tsc', ['.d.ts']);
+  }
+
   if (!fs.existsSync(path.join(process.cwd(), '.skip-build'))) {
     const srcHeader = `// Copyright 2017-${new Date().getFullYear()} ${name} authors & contributors\n// SPDX-License-Identifier: Apache-2.0\n`;
     const genHeader = `${srcHeader}\n// Do not edit, auto-generated by @polkadot/dev\n`;
diff --git a/yarn.lock b/yarn.lock
index 9ef9143e..8871d890 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -433,7 +433,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@polkadot/dev-test@npm:^0.80.1, @polkadot/dev-test@workspace:packages/dev-test":
+"@polkadot/dev-test@npm:^0.81.0, @polkadot/dev-test@workspace:packages/dev-test":
   version: 0.0.0-use.local
   resolution: "@polkadot/dev-test@workspace:packages/dev-test"
   dependencies:
@@ -443,7 +443,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@polkadot/dev-ts@npm:^0.80.1, @polkadot/dev-ts@workspace:packages/dev-ts":
+"@polkadot/dev-ts@npm:^0.81.0, @polkadot/dev-ts@workspace:packages/dev-ts":
   version: 0.0.0-use.local
   resolution: "@polkadot/dev-ts@workspace:packages/dev-ts"
   dependencies:
@@ -458,8 +458,8 @@ __metadata:
   resolution: "@polkadot/dev@workspace:packages/dev"
   dependencies:
     "@eslint/js": "npm:^8.56.0"
-    "@polkadot/dev-test": "npm:^0.80.1"
-    "@polkadot/dev-ts": "npm:^0.80.1"
+    "@polkadot/dev-test": "npm:^0.81.0"
+    "@polkadot/dev-ts": "npm:^0.81.0"
     "@rollup/plugin-alias": "npm:^5.1.0"
     "@rollup/plugin-commonjs": "npm:^25.0.7"
     "@rollup/plugin-dynamic-import-vars": "npm:^2.1.2"