diff --git a/packages/plugin-react/src/index.ts b/packages/plugin-react/src/index.ts
index 3dba7be8f..a147b5e17 100644
--- a/packages/plugin-react/src/index.ts
+++ b/packages/plugin-react/src/index.ts
@@ -172,7 +172,10 @@ export default function viteReact(opts: Options = {}): Plugin[] {
             {
               tag: 'script',
               attrs: { type: 'module' },
-              children: getPreambleCode(base),
+              // In bundled dev mode, Rolldown resolves module specifiers at build
+              // time without URL-level base stripping, so we must use '/' instead
+              // of config.base to match the resolveId hook for '/@react-refresh'.
+              children: getPreambleCode('/'),
             },
           ]
       },
diff --git a/playground/bundled-dev-base-path/App.jsx b/playground/bundled-dev-base-path/App.jsx
new file mode 100644
index 000000000..996aa4af2
--- /dev/null
+++ b/playground/bundled-dev-base-path/App.jsx
@@ -0,0 +1,15 @@
+import { useState } from 'react'
+
+function App() {
+  const [count, setCount] = useState(0)
+  return (
+    <div>
+      <h1>bundledDev + base path</h1>
+      <button id="state-button" onClick={() => setCount((c) => c + 1)}>
+        count is: {count}
+      </button>
+    </div>
+  )
+}
+
+export default App
diff --git a/playground/bundled-dev-base-path/__tests__/bundled-dev-base-path.spec.ts b/playground/bundled-dev-base-path/__tests__/bundled-dev-base-path.spec.ts
new file mode 100644
index 000000000..5b04223f3
--- /dev/null
+++ b/playground/bundled-dev-base-path/__tests__/bundled-dev-base-path.spec.ts
@@ -0,0 +1,29 @@
+import { expect, test } from 'vitest'
+import { browserErrors, isServe, page, viteTestUrl } from '~utils'
+
+// Regression test for https://github.com/vitejs/vite-plugin-react/issues/1190
+// bundledDev mode with a non-root base should not fail to resolve /@react-refresh.
+test.runIf(isServe)(
+  'should load without UNRESOLVED_IMPORT error for @react-refresh',
+  async () => {
+    await page.goto(viteTestUrl)
+    // bundledDev shows "Bundling in progress" until the first bundle is ready.
+    await page.waitForSelector('h1')
+    await expect
+      .poll(() => page.textContent('h1'))
+      .toMatch('bundledDev + base path')
+    expect(browserErrors).toHaveLength(0)
+  },
+)
+
+test.runIf(isServe)('should render and update state', async () => {
+  await page.goto(viteTestUrl)
+  await page.waitForSelector('#state-button')
+  await expect
+    .poll(() => page.textContent('#state-button'))
+    .toMatch('count is: 0')
+  await page.click('#state-button')
+  await expect
+    .poll(() => page.textContent('#state-button'))
+    .toMatch('count is: 1')
+})
diff --git a/playground/bundled-dev-base-path/index.html b/playground/bundled-dev-base-path/index.html
new file mode 100644
index 000000000..7417c442d
--- /dev/null
+++ b/playground/bundled-dev-base-path/index.html
@@ -0,0 +1,10 @@
+<div id="app"></div>
+<script type="module">
+  import React from 'react'
+  import ReactDOM from 'react-dom/client'
+  import App from './App.jsx'
+
+  ReactDOM.createRoot(document.getElementById('app')).render(
+    React.createElement(App),
+  )
+</script>
diff --git a/playground/bundled-dev-base-path/package.json b/playground/bundled-dev-base-path/package.json
new file mode 100644
index 000000000..873ffc10e
--- /dev/null
+++ b/playground/bundled-dev-base-path/package.json
@@ -0,0 +1,17 @@
+{
+  "name": "@vitejs/test-bundled-dev-base-path",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "react": "^19.2.5",
+    "react-dom": "^19.2.5"
+  },
+  "devDependencies": {
+    "@vitejs/plugin-react": "workspace:*"
+  }
+}
diff --git a/playground/bundled-dev-base-path/vite.config.ts b/playground/bundled-dev-base-path/vite.config.ts
new file mode 100644
index 000000000..23ca63dd7
--- /dev/null
+++ b/playground/bundled-dev-base-path/vite.config.ts
@@ -0,0 +1,13 @@
+import react from '@vitejs/plugin-react'
+import type { UserConfig } from 'vite'
+
+const config: UserConfig = {
+  server: { port: 8930 /* Should be unique */ },
+  mode: 'development',
+  base: '/static/',
+  plugins: [react()],
+  experimental: { bundledDev: true },
+  build: { minify: false },
+}
+
+export default config
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index eb61aaccd..7aec66268 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -793,6 +793,19 @@ importers:
         specifier: ^3.3.2
         version: 3.3.2
 
+  playground/bundled-dev-base-path:
+    dependencies:
+      react:
+        specifier: ^19.2.5
+        version: 19.2.5
+      react-dom:
+        specifier: ^19.2.5
+        version: 19.2.5(react@19.2.5)
+    devDependencies:
+      '@vitejs/plugin-react':
+        specifier: workspace:*
+        version: link:../../packages/plugin-react
+
   playground/class-components:
     dependencies:
       react: