diff --git a/shared/package.json b/shared/package.json
index 3377f3d..ee97032 100644
--- a/shared/package.json
+++ b/shared/package.json
@@ -5,8 +5,8 @@
   "type": "module",
   "scripts": {
     "prebuild": "barrelsby --directory src --delete --single",
-    "build:esm": "tsc -p tsconfig.esm.json",
-    "build:cjs": "tsc -p tsconfig.cjs.json",
+    "build:esm": "tsc -p tsconfig.esm.json && node scripts/postbuild-esm.cjs",
+    "build:cjs": "tsc -p tsconfig.cjs.json && find dist/cjs -name \"*.js\" -type f -exec sh -c 'mv \"$1\" \"${1%.js}.cjs\"' _ {} \\; && node scripts/postbuild.cjs",
     "build": "npm run prebuild && npm run build:esm && npm run build:cjs",
     "lint": "eslint ."
   },
@@ -14,7 +14,7 @@
     ".": {
       "types": "./dist/types/index.d.ts",
       "import": "./dist/esm/index.js",
-      "require": "./dist/cjs/index.js"
+      "require": "./dist/cjs/index.cjs"
     }
   },
   "types": "./dist/types/index.d.ts",
diff --git a/shared/scripts/postbuild-esm.cjs b/shared/scripts/postbuild-esm.cjs
new file mode 100644
index 0000000..e236e53
--- /dev/null
+++ b/shared/scripts/postbuild-esm.cjs
@@ -0,0 +1,30 @@
+const fs = require('fs');
+const path = require('path');
+
+// Recursively process all .js files in esm directory
+function processDirectory(dir) {
+  const files = fs.readdirSync(dir);
+  
+  files.forEach(file => {
+    const filePath = path.join(dir, file);
+    const stat = fs.statSync(filePath);
+    
+    if (stat.isDirectory()) {
+      processDirectory(filePath);
+    } else if (file.endsWith('.js')) {
+      // Read the file
+      let content = fs.readFileSync(filePath, 'utf8');
+      
+      // Replace import/export statements to add .js extension
+      // Replace from "./path" with from "./path.js" (for relative imports only)
+      content = content.replace(/from ["'](\.[^"']*?)(?<!\.js)["']/g, 'from "$1.js"');
+      
+      // Write back
+      fs.writeFileSync(filePath, content, 'utf8');
+      console.log(`✓ Updated ${filePath}`);
+    }
+  });
+}
+
+processDirectory('./dist/esm');
+console.log('✓ ESM post-build processing complete');
diff --git a/shared/scripts/postbuild.cjs b/shared/scripts/postbuild.cjs
new file mode 100644
index 0000000..597c6f3
--- /dev/null
+++ b/shared/scripts/postbuild.cjs
@@ -0,0 +1,29 @@
+const fs = require('fs');
+const path = require('path');
+
+// Recursively process all .cjs files
+function processDirectory(dir) {
+  const files = fs.readdirSync(dir);
+  
+  files.forEach(file => {
+    const filePath = path.join(dir, file);
+    const stat = fs.statSync(filePath);
+    
+    if (stat.isDirectory()) {
+      processDirectory(filePath);
+    } else if (file.endsWith('.cjs')) {
+      // Read the file
+      let content = fs.readFileSync(filePath, 'utf8');
+      
+      // Replace require statements to add .cjs extension
+      content = content.replace(/require\("([^"]*?)(?<!\.cjs)"\)/g, 'require("$1.cjs")');
+      
+      // Write back
+      fs.writeFileSync(filePath, content, 'utf8');
+      console.log(`✓ Updated ${filePath}`);
+    }
+  });
+}
+
+processDirectory('./dist/cjs');
+console.log('✓ Post-build processing complete');