diff --git a/packages/wxt/src/core/builders/vite/index.ts b/packages/wxt/src/core/builders/vite/index.ts
index 59d59d1e..520511c6 100644
--- a/packages/wxt/src/core/builders/vite/index.ts
+++ b/packages/wxt/src/core/builders/vite/index.ts
@@ -218,7 +218,7 @@ export async function createViteBuilder(
           const baseConfig = await getBaseConfig();
           const envConfig: vite.InlineConfig = {
             plugins: [
-              wxtPlugins.webextensionPolyfillMock(wxtConfig),
+              wxtPlugins.extensionApiMock(wxtConfig),
               wxtPlugins.removeEntrypointMainFunction(wxtConfig, path),
             ],
           };
@@ -238,7 +238,7 @@ export async function createViteBuilder(
           baseConfig.optimizeDeps.include = [];
           const envConfig: vite.InlineConfig = {
             plugins: [
-              wxtPlugins.webextensionPolyfillMock(wxtConfig),
+              wxtPlugins.extensionApiMock(wxtConfig),
               wxtPlugins.removeEntrypointMainFunction(wxtConfig, path),
             ],
           };
diff --git a/packages/wxt/src/core/builders/vite/plugins/extensionApiMock.ts b/packages/wxt/src/core/builders/vite/plugins/extensionApiMock.ts
new file mode 100644
index 00000000..370d37bc
--- /dev/null
+++ b/packages/wxt/src/core/builders/vite/plugins/extensionApiMock.ts
@@ -0,0 +1,38 @@
+import path from 'node:path';
+import type * as vite from 'vite';
+import { ResolvedConfig } from '../../../../types';
+
+/**
+ * Mock `webextension-polyfill`, `wxt/browser`, and `wxt/browser/*` by inlining
+ * all dependencies that import them and adding a custom alias so that Vite
+ * resolves to a mocked version of the module.
+ *
+ * TODO: Detect non-wxt dependencies (like `@webext-core/*`) that import `webextension-polyfill` via
+ * `npm list` and inline them automatically.
+ */
+export function extensionApiMock(config: ResolvedConfig): vite.PluginOption {
+  return {
+    name: 'wxt:extension-api-mock',
+    config() {
+      const mockBrowser = path.resolve(
+        config.wxtModuleDir,
+        'dist/virtual/mock-browser',
+      );
+      return {
+        resolve: {
+          alias: {
+            'webextension-polyfill': mockBrowser,
+            'wxt/browser': mockBrowser,
+            'wxt/browser/webextension-polyfill': mockBrowser,
+            'wxt/browser/chrome': mockBrowser,
+          },
+        },
+        ssr: {
+          // Inline all WXT modules so vite processes them so the aliases can
+          // be resolved
+          noExternal: ['wxt'],
+        },
+      };
+    },
+  };
+}
diff --git a/packages/wxt/src/core/builders/vite/plugins/index.ts b/packages/wxt/src/core/builders/vite/plugins/index.ts
index cbd8967b..f70dde24 100644
--- a/packages/wxt/src/core/builders/vite/plugins/index.ts
+++ b/packages/wxt/src/core/builders/vite/plugins/index.ts
@@ -8,7 +8,7 @@ export * from './noopBackground';
 export * from './cssEntrypoints';
 export * from './bundleAnalysis';
 export * from './globals';
-export * from './webextensionPolyfillMock';
+export * from './extensionApiMock';
 export * from './resolveExtensionApi';
 export * from './entrypointGroupGlobals';
 export * from './defineImportMeta';
diff --git a/packages/wxt/src/core/builders/vite/plugins/webextensionPolyfillMock.ts b/packages/wxt/src/core/builders/vite/plugins/webextensionPolyfillMock.ts
deleted file mode 100644
index 99d84bf2..00000000
--- a/packages/wxt/src/core/builders/vite/plugins/webextensionPolyfillMock.ts
+++ /dev/null
@@ -1,43 +0,0 @@
-import path from 'node:path';
-import type * as vite from 'vite';
-import { ResolvedConfig } from '../../../../types';
-
-/**
- * Mock `webextension-polyfill` by inlining all dependencies that import it and adding a custom
- * alias so that Vite resolves to a mocked version of the module.
- *
- * There are two ways to mark a module as inline:
- * 1. Use partial file paths ("wxt/dist/browser.js") in the `test.server.deps.inline` option.
- * 2. Use module names ("wxt" or "@webext-core/messaging") in the `ssr.noExternalize` option.
- *
- * This plugin uses the second approach since it's a little more intuative to understand.
- *
- * TODO: Detect non-wxt dependencies (like `@webext-core/*`) that import `webextension-polyfill` via
- * `npm list` and inline them automatically.
- */
-export function webextensionPolyfillMock(
-  config: ResolvedConfig,
-): vite.PluginOption {
-  return {
-    name: 'wxt:testing-inline-deps',
-    config() {
-      return {
-        resolve: {
-          alias: {
-            // Alias to use a mocked version of the polyfill
-            'webextension-polyfill': path.resolve(
-              config.wxtModuleDir,
-              'dist/virtual/mock-browser',
-            ),
-            'wxt/browser': 'wxt/testing',
-            'wxt/browser/chrome': 'wxt/testing',
-          },
-        },
-        ssr: {
-          // Inline all WXT modules
-          noExternal: ['wxt'],
-        },
-      };
-    },
-  };
-}
diff --git a/packages/wxt/src/testing/wxt-vitest-plugin.ts b/packages/wxt/src/testing/wxt-vitest-plugin.ts
index 2f8dd744..5495dba2 100644
--- a/packages/wxt/src/testing/wxt-vitest-plugin.ts
+++ b/packages/wxt/src/testing/wxt-vitest-plugin.ts
@@ -3,7 +3,7 @@ import {
   download,
   tsconfigPaths,
   globals,
-  webextensionPolyfillMock,
+  extensionApiMock,
   resolveAppConfig,
 } from '../core/builders/vite/plugins';
 import { resolveConfig } from '../core/utils/building';
@@ -26,20 +26,23 @@ import { createUnimport } from 'unimport';
  *
  * @param inlineConfig Customize WXT's config for testing. Any config specified here overrides the config from your `wxt.config.ts` file.
  */
-export function WxtVitest(inlineConfig?: InlineConfig): vite.PluginOption {
-  return resolveConfig(inlineConfig ?? {}, 'serve').then(async (config) => {
-    const plugins = [
-      webextensionPolyfillMock(config),
-      globals(config),
-      download(config),
-      tsconfigPaths(config),
-      resolveAppConfig(config),
-    ];
-    if (config.imports !== false) {
-      const unimport = createUnimport(config.imports);
-      await unimport.init();
-      plugins.push(unimportPlugin(unimport));
-    }
-    return plugins;
-  });
+export async function WxtVitest(
+  inlineConfig?: InlineConfig,
+): Promise<vite.PluginOption[]> {
+  const config = await resolveConfig(inlineConfig ?? {}, 'serve');
+
+  const plugins: vite.PluginOption[] = [
+    globals(config),
+    download(config),
+    tsconfigPaths(config),
+    resolveAppConfig(config),
+    extensionApiMock(config),
+  ];
+  if (config.imports !== false) {
+    const unimport = createUnimport(config.imports);
+    await unimport.init();
+    plugins.push(unimportPlugin(unimport));
+  }
+
+  return plugins;
 }
diff --git a/packages/wxt/src/virtual/fake-browser-webextension-polyfill.ts b/packages/wxt/src/virtual/fake-browser-webextension-polyfill.ts
deleted file mode 100644
index 60156bd6..00000000
--- a/packages/wxt/src/virtual/fake-browser-webextension-polyfill.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-import { fakeBrowser } from 'wxt/testing';
-
-export const browser = fakeBrowser;
diff --git a/packages/wxt/src/virtual/mock-browser.ts b/packages/wxt/src/virtual/mock-browser.ts
index cf37d2f7..38024710 100644
--- a/packages/wxt/src/virtual/mock-browser.ts
+++ b/packages/wxt/src/virtual/mock-browser.ts
@@ -1,3 +1,4 @@
-import { fakeBrowser as mockBrowser } from 'wxt/testing';
+import { fakeBrowser } from 'wxt/testing';
 
-export default mockBrowser;
+export const browser = fakeBrowser;
+export default fakeBrowser;
diff --git a/packages/wxt/src/virtual/virtual-module-globals.d.ts b/packages/wxt/src/virtual/virtual-module-globals.d.ts
index ba96b54f..5199a83a 100644
--- a/packages/wxt/src/virtual/virtual-module-globals.d.ts
+++ b/packages/wxt/src/virtual/virtual-module-globals.d.ts
@@ -1,26 +1,22 @@
 // Types required to make the virtual modules happy.
 
 declare module 'virtual:user-background-entrypoint' {
-  const definition: { main: () => void };
+  const definition: import('wxt').BackgroundDefinition;
   export default definition;
 }
 
 declare module 'virtual:user-content-script-isolated-world-entrypoint' {
-  const definition: {
-    main: (
-      ctx: import('wxt/client').ContentScriptContext,
-    ) => void | Promise<void>;
-  };
+  const definition: import('wxt').IsolatedWorldContentScriptDefinition;
   export default definition;
 }
 
 declare module 'virtual:user-content-script-main-world-entrypoint' {
-  const definition: { main: () => void | Promise<void> };
+  const definition: import('wxt').MainWorldContentScriptDefinition;
   export default definition;
 }
 
 declare module 'virtual:user-unlisted-script-entrypoint' {
-  const definition: { main: () => void | Promise<void> };
+  const definition: import('wxt').UnlistedScriptDefinition;
   export default definition;
 }
 
@@ -28,16 +24,6 @@ declare module 'wxt/browser' {
   export const browser: import('webextension-polyfill').Browser;
 }
 
-declare module 'wxt/client' {
-  export class ContentScriptContext {
-    constructor(name: string, options: any);
-  }
-}
-
-declare module 'wxt/testing' {
-  export const fakeBrowser: import('webextension-polyfill').Browser;
-}
-
 declare module 'virtual:wxt-plugins' {
   export function initPlugins(): void;
 }