diff --git a/dev-packages/browser-integration-tests/suites/profiling/manualMode/subject.js b/dev-packages/browser-integration-tests/suites/profiling/manualMode/subject.js
index 906f14d06693..fbb4f927e276 100644
--- a/dev-packages/browser-integration-tests/suites/profiling/manualMode/subject.js
+++ b/dev-packages/browser-integration-tests/suites/profiling/manualMode/subject.js
@@ -53,7 +53,8 @@ Sentry.uiProfiler.startProfiler();
 fibonacci(40);
 await new Promise(resolve => setTimeout(resolve, 25));
 
-largeSum();
+// Enough iterations that largeSum stays on-stack across several profiler ticks (10ms interval); otherwise sampling can miss it entirely.
+largeSum(2_500_000);
 await new Promise(resolve => setTimeout(resolve, 25));
 
 Sentry.uiProfiler.stopProfiler();
diff --git a/dev-packages/browser-integration-tests/suites/profiling/manualMode/test.ts b/dev-packages/browser-integration-tests/suites/profiling/manualMode/test.ts
index 176caad92af6..128f5cb1aeb5 100644
--- a/dev-packages/browser-integration-tests/suites/profiling/manualMode/test.ts
+++ b/dev-packages/browser-integration-tests/suites/profiling/manualMode/test.ts
@@ -37,7 +37,7 @@ sentryTest('sends profile_chunk envelopes in manual mode', async ({ page, getLoc
   const profileChunkEnvelopes = await getMultipleSentryEnvelopeRequests<ProfileChunkEnvelope>(
     page,
     2,
-    { url, envelopeType: 'profile_chunk', timeout: 8000 },
+    { url, envelopeType: 'profile_chunk', timeout: 15_000 },
     properFullEnvelopeRequestParser,
   );