diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 4b9d5ec1f8be..ae90621dc220 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -583,6 +583,7 @@ jobs:
         bundle:
           - loader_base
           - loader_eager
+          - loader_debug
           - loader_tracing
           - loader_replay
           - loader_tracing_replay
diff --git a/packages/browser-integration-tests/fixtures/loader.js b/packages/browser-integration-tests/fixtures/loader.js
index 36d7d2401856..e8e84a3a7a9a 100644
--- a/packages/browser-integration-tests/fixtures/loader.js
+++ b/packages/browser-integration-tests/fixtures/loader.js
@@ -1,4 +1,4 @@
-!function(n,e,r,t,a,i,o,c,_,f){for(var p=f,forceLoad=!1,s=0;s<document.scripts.length;s++)if(document.scripts[s].src.indexOf(o)>-1){p&&"no"===document.scripts[s].getAttribute("data-lazy")&&(p=!1);break}var u=!1,l=[],d=function(n){("e"in n||"p"in n||n.f&&n.f.indexOf("capture")>-1||n.f&&n.f.indexOf("showReportDialog")>-1)&&p&&R(l),d.data.push(n)};function R(o){if(!u){u=!0;var f=e.scripts[0],p=e.createElement(r);p.src=c,p.crossOrigin="anonymous",p.addEventListener("load",(function(){try{n[t]&&n[t].__SENTRY_LOADER__&&(n[t]=E),n[a]&&n[a].__SENTRY_LOADER__&&(n[a]=v),n.SENTRY_SDK_SOURCE="loader";var e=n[i],r=e.init;e.init=function(n){var t=_;for(var a in n)Object.prototype.hasOwnProperty.call(n,a)&&(t[a]=n[a]);!function(n,e){var r=n.integrations||[];if(!Array.isArray(r))return;var t=r.map((function(n){return n.name}));n.tracesSampleRate&&-1===t.indexOf("BrowserTracing")&&r.push(new e.BrowserTracing);(n.replaysSessionSampleRate||n.replaysOnErrorSampleRate)&&-1===t.indexOf("Replay")&&r.push(new e.Replay);n.integrations=r}(t,e),r(t)},function(e,r){try{for(var i=0;i<e.length;i++)"function"==typeof e[i]&&e[i]();var o=d.data,c=!(void 0===(u=n.__SENTRY__)||!u.hub||!u.hub.getClient());o.sort((function(n){return"init"===n.f?-1:0}));var _=!1;for(i=0;i<o.length;i++)if(o[i].f){_=!0;var f=o[i];!1===c&&"init"!==f.f&&r.init(),c=!0,r[f.f].apply(r,f.a)}!1===c&&!1===_&&r.init();var p=n[t],s=n[a];for(i=0;i<o.length;i++)"e"in o[i]&&p?p.apply(n,o[i].e):"p"in o[i]&&s&&s.apply(n,[o[i].p])}catch(n){console.error(n)}var u}(o,e)}catch(n){console.error(n)}})),f.parentNode.insertBefore(p,f)}}d.data=[],n[i]=n[i]||{},n[i].onLoad=function(n){l.push(n),p&&!forceLoad||R(l)},n[i].forceLoad=function(){forceLoad=!0,p&&setTimeout((function(){R(l)}))},["init","addBreadcrumb","captureMessage","captureException","captureEvent","configureScope","withScope","showReportDialog"].forEach((function(e){n[i][e]=function(){d({f:e,a:arguments})}}));var E=n[t];n[t]=function(){d({e:[].slice.call(arguments)}),E&&E.apply(n,arguments)},n[t].__SENTRY_LOADER__=!0;var v=n[a];n[a]=function(e){d({p:"reason"in e?e.reason:"detail"in e&&"reason"in e.detail?e.detail.reason:e}),v&&v.apply(n,arguments)},n[a].__SENTRY_LOADER__=!0,p||setTimeout((function(){R(l)}))}
+!function(n,e,r,t,i,o,a,c,s,f){for(var u=f,forceLoad=!1,p=0;p<document.scripts.length;p++)if(document.scripts[p].src.indexOf(a)>-1){u&&"no"===document.scripts[p].getAttribute("data-lazy")&&(u=!1);break}var d=!1,l=[],_=function(n){("e"in n||"p"in n||n.f&&n.f.indexOf("capture")>-1||n.f&&n.f.indexOf("showReportDialog")>-1)&&u&&E(l),_.data.push(n)};function v(){_({e:[].slice.call(arguments)})}function h(n){_({p:"reason"in n?n.reason:"detail"in n&&"reason"in n.detail?n.detail.reason:n})}function E(a){if(!d){d=!0;var f=e.scripts[0],u=e.createElement(r);u.src=c,u.crossOrigin="anonymous",u.addEventListener("load",(function(){try{n.removeEventListener("error",v),n.removeEventListener("unhandledrejection",h),n.SENTRY_SDK_SOURCE="loader";var e=n[o],r=e.init;e.init=function(n){var t=s;for(var i in n)Object.prototype.hasOwnProperty.call(n,i)&&(t[i]=n[i]);!function(n,e){var r=n.integrations||[];if(!Array.isArray(r))return;var t=r.map((function(n){return n.name}));n.tracesSampleRate&&-1===t.indexOf("BrowserTracing")&&r.push(new e.BrowserTracing);(n.replaysSessionSampleRate||n.replaysOnErrorSampleRate)&&-1===t.indexOf("Replay")&&r.push(new e.Replay);n.integrations=r}(t,e),r(t)},function(e,r){try{for(var o=0;o<e.length;o++)"function"==typeof e[o]&&e[o]();var a=_.data,c=!(void 0===(d=n.__SENTRY__)||!d.hub||!d.hub.getClient());a.sort((function(n){return"init"===n.f?-1:0}));var s=!1;for(o=0;o<a.length;o++)if(a[o].f){s=!0;var f=a[o];!1===c&&"init"!==f.f&&r.init(),c=!0,r[f.f].apply(r,f.a)}!1===c&&!1===s&&r.init();var u=n[t],p=n[i];for(o=0;o<a.length;o++)"e"in a[o]&&u?u.apply(n,a[o].e):"p"in a[o]&&p&&p.apply(n,[a[o].p])}catch(n){console.error(n)}var d}(a,e)}catch(n){console.error(n)}})),f.parentNode.insertBefore(u,f)}}_.data=[],n[o]=n[o]||{},n[o].onLoad=function(n){l.push(n),u&&!forceLoad||E(l)},n[o].forceLoad=function(){forceLoad=!0,u&&setTimeout((function(){E(l)}))},["init","addBreadcrumb","captureMessage","captureException","captureEvent","configureScope","withScope","showReportDialog"].forEach((function(e){n[o][e]=function(){_({f:e,a:arguments})}})),window.addEventListener("error",v),window.addEventListener("unhandledrejection",h),u||setTimeout((function(){E(l)}))}
 (
   window,
   document,
diff --git a/packages/browser-integration-tests/loader-suites/loader/noOnLoad/captureException/test.ts b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/captureException/test.ts
index e7441a654724..896ba2d53c0a 100644
--- a/packages/browser-integration-tests/loader-suites/loader/noOnLoad/captureException/test.ts
+++ b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/captureException/test.ts
@@ -1,7 +1,7 @@
 import { expect } from '@playwright/test';
 
 import { sentryTest } from '../../../../utils/fixtures';
-import { envelopeRequestParser,waitForErrorRequest } from '../../../../utils/helpers';
+import { envelopeRequestParser, waitForErrorRequest } from '../../../../utils/helpers';
 
 sentryTest('captureException works', async ({ getLocalTestUrl, page }) => {
   const req = waitForErrorRequest(page);
diff --git a/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/subject.js b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/subject.js
new file mode 100644
index 000000000000..405fb09bbac5
--- /dev/null
+++ b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/subject.js
@@ -0,0 +1,8 @@
+const oldOnError = window.onerror;
+
+window.onerror = function () {
+  console.log('custom error');
+  oldOnError && oldOnError.apply(this, arguments);
+};
+
+window.doSomethingWrong();
diff --git a/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/test.ts b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/test.ts
new file mode 100644
index 000000000000..96c49a49ab4c
--- /dev/null
+++ b/packages/browser-integration-tests/loader-suites/loader/noOnLoad/customOnErrorHandler/test.ts
@@ -0,0 +1,15 @@
+import { expect } from '@playwright/test';
+
+import { sentryTest } from '../../../../utils/fixtures';
+import { envelopeRequestParser, waitForErrorRequest } from '../../../../utils/helpers';
+
+sentryTest('error handler works with a recursive custom error handler', async ({ getLocalTestUrl, page }) => {
+  const req = waitForErrorRequest(page);
+
+  const url = await getLocalTestUrl({ testDir: __dirname });
+  await page.goto(url);
+
+  const eventData = envelopeRequestParser(await req);
+  expect(eventData.exception?.values?.length).toBe(1);
+  expect(eventData.exception?.values?.[0]?.value).toBe('window.doSomethingWrong is not a function');
+});
diff --git a/packages/browser-integration-tests/loader-suites/loader/onLoad/captureException/test.ts b/packages/browser-integration-tests/loader-suites/loader/onLoad/captureException/test.ts
index e7441a654724..896ba2d53c0a 100644
--- a/packages/browser-integration-tests/loader-suites/loader/onLoad/captureException/test.ts
+++ b/packages/browser-integration-tests/loader-suites/loader/onLoad/captureException/test.ts
@@ -1,7 +1,7 @@
 import { expect } from '@playwright/test';
 
 import { sentryTest } from '../../../../utils/fixtures';
-import { envelopeRequestParser,waitForErrorRequest } from '../../../../utils/helpers';
+import { envelopeRequestParser, waitForErrorRequest } from '../../../../utils/helpers';
 
 sentryTest('captureException works', async ({ getLocalTestUrl, page }) => {
   const req = waitForErrorRequest(page);
diff --git a/packages/browser-integration-tests/package.json b/packages/browser-integration-tests/package.json
index c8b9c92d19e8..61645e7960e5 100644
--- a/packages/browser-integration-tests/package.json
+++ b/packages/browser-integration-tests/package.json
@@ -39,6 +39,7 @@
     "test:loader:tracing": "PW_BUNDLE=loader_tracing yarn test:loader",
     "test:loader:replay": "PW_BUNDLE=loader_replay yarn test:loader",
     "test:loader:full": "PW_BUNDLE=loader_tracing_replay yarn test:loader",
+    "test:loader:debug": "PW_BUNDLE=loader_debug yarn test:loader",
     "test:ci": "playwright test ./suites --browser='all' --reporter='line'",
     "test:update-snapshots": "yarn test --update-snapshots --browser='all' && yarn test --update-snapshots",
     "test:detect-flaky": "ts-node scripts/detectFlakyTests.ts",
diff --git a/packages/browser-integration-tests/utils/generatePage.ts b/packages/browser-integration-tests/utils/generatePage.ts
index a3bd1d7c8991..4a6afb3eab2e 100644
--- a/packages/browser-integration-tests/utils/generatePage.ts
+++ b/packages/browser-integration-tests/utils/generatePage.ts
@@ -11,17 +11,22 @@ const LOADER_TEMPLATE = readFileSync(path.join(__dirname, '../fixtures/loader.js
 
 const LOADER_CONFIGS: Record<string, { bundle: string; options: Record<string, unknown>; lazy: boolean }> = {
   loader_base: {
-    bundle: 'browser/build/bundles/bundle.es5.js',
+    bundle: 'browser/build/bundles/bundle.es5.min.js',
     options: {},
     lazy: true,
   },
   loader_eager: {
-    bundle: 'browser/build/bundles/bundle.es5.js',
+    bundle: 'browser/build/bundles/bundle.es5.min.js',
     options: {},
     lazy: false,
   },
+  loader_debug: {
+    bundle: 'browser/build/bundles/bundle.es5.debug.min.js',
+    options: { debug: true },
+    lazy: true,
+  },
   loader_tracing: {
-    bundle: 'browser/build/bundles/bundle.tracing.es5.js',
+    bundle: 'browser/build/bundles/bundle.tracing.es5.min.js',
     options: { tracesSampleRate: 1 },
     lazy: false,
   },