diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index e7386a2..bc4e3b0 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -135,6 +135,8 @@ jobs:
       - name: Build extension
         working-directory: ./packages/extension
         run: npm run build
+        env:
+          SET_EXTENSION_PUBLIC_KEY_IN_MANIFEST: 1
       - name: Get extension version
         id: get-version
         working-directory: ./packages/extension
diff --git a/packages/extension/vite.config.mts b/packages/extension/vite.config.mts
index 89ec56c..b5c7680 100644
--- a/packages/extension/vite.config.mts
+++ b/packages/extension/vite.config.mts
@@ -19,6 +19,10 @@ import { defineConfig } from 'vite';
 import react from '@vitejs/plugin-react';
 import { viteStaticCopy } from 'vite-plugin-static-copy';
 
+// Public key matching the Chrome Web Store listing — used to fix the extension ID across installs.
+// Set SET_EXTENSION_PUBLIC_KEY_IN_MANIFEST=1 in release builds to inject it into the manifest.
+const extensionPublicKey = 'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwRsUUO4mmbCi4JpmrIoIw31iVW9+xUJRZ6nSzya17PQkaUPDxe1IpgM+vpd/xB6mJWlJSyE1Lj95c0sbomGfVY1M0zUeKbaRVcAb+/a6m59gNR+ubFlmTX0nK9/8fE2FpRB9D+4N5jyeIPQuASW/0oswI2/ijK7hH5NTRX8gWc/ROMSgUj7rKhTAgBrICt/NsStgDPsxRTPPJnhJ/ViJtM1P5KsSYswE987DPoFnpmkFpq8g1ae0eYbQfXy55ieaacC4QWyJPj3daU2kMfBQw7MXnnk0H/WDxouMOIHnd8MlQxpEMqAihj7KpuONH+MUhuj9HEQo4df6bSaIuQ0b4QIDAQAB';
+
 // https://vitejs.dev/config/
 export default defineConfig({
   plugins: [
@@ -31,7 +35,14 @@ export default defineConfig({
         },
         {
           src: '../../manifest.json',
-          dest: '.'
+          dest: '.',
+          ...(!!process.env.SET_EXTENSION_PUBLIC_KEY_IN_MANIFEST ? {
+            transform: (content: string) => {
+              const manifest = JSON.parse(content);
+              manifest.key = extensionPublicKey;
+              return JSON.stringify(manifest, null, 2);
+            }
+          } : {})
         }
       ]
     })