diff --git a/dev-packages/browser-integration-tests/utils/generatePage.ts b/dev-packages/browser-integration-tests/utils/generatePage.ts
index a74cd7dfe7bb..463bd9e26716 100644
--- a/dev-packages/browser-integration-tests/utils/generatePage.ts
+++ b/dev-packages/browser-integration-tests/utils/generatePage.ts
@@ -2,7 +2,7 @@ import { mkdirSync } from 'fs';
 import HtmlWebpackPlugin from 'html-webpack-plugin';
 import webpack from 'webpack';
 import webpackConfig from '../webpack.config';
-import SentryScenarioGenerationPlugin from './generatePlugin';
+import SentryScenarioGenerationPlugin, { useLoader } from './generatePlugin';
 
 export async function generatePage(
   initPath: string,
@@ -30,6 +30,9 @@ export async function generatePage(
             filename: outPageName,
             template: templatePath,
             inject: 'body',
+            // Deferred scripts may run after the loader has swapped in the CDN bundle but before it calls
+            // `init()`, so their SDK calls would be dropped. Blocking scripts always hit the loader stub.
+            scriptLoading: useLoader ? 'blocking' : 'defer',
           }),
         ],
       }),
diff --git a/dev-packages/browser-integration-tests/utils/generatePlugin.ts b/dev-packages/browser-integration-tests/utils/generatePlugin.ts
index b7a8b803a243..3dfdbb25288c 100644
--- a/dev-packages/browser-integration-tests/utils/generatePlugin.ts
+++ b/dev-packages/browser-integration-tests/utils/generatePlugin.ts
@@ -19,7 +19,7 @@ const useCompiledModule = bundleKey === 'esm' || bundleKey === 'cjs';
 
 // Bundles need to be injected into HTML before Sentry initialization.
 const useBundleOrLoader = bundleKey && !useCompiledModule;
-const useLoader = bundleKey.startsWith('loader');
+export const useLoader = bundleKey.startsWith('loader');
 
 // These are imports that, when using CDN bundles, are not included in the main CDN bundle.
 // In this case, if we encounter this import, we want to add this CDN bundle file instead