diff --git a/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/init.js b/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/init.js
new file mode 100644
index 000000000000..05b690d85393
--- /dev/null
+++ b/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/init.js
@@ -0,0 +1,30 @@
+import * as Sentry from '@sentry/browser';
+import { addLcpInstrumentationHandler } from '@sentry/browser-utils';
+
+window.Sentry = Sentry;
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  integrations: [Sentry.browserTracingIntegration()],
+  tracesSampleRate: 1,
+});
+
+// Registered in the bundle of the SDK, so the handlers share its LCP observer. A second bundle gets
+// a copy of the instrumentation with an observer of its own, whose view of the LCP candidates can
+// differ from the SDK's (e.g. a different first-hidden time), which made this test flaky.
+addLcpInstrumentationHandler(({ metric }) => {
+  const entry = metric.entries[metric.entries.length - 1];
+  window._LCP = entry.size;
+});
+
+addLcpInstrumentationHandler(({ metric }) => {
+  const entry = metric.entries[metric.entries.length - 1];
+  window._LCP2 = entry.size;
+});
+
+window.ADD_HANDLER = () => {
+  addLcpInstrumentationHandler(({ metric }) => {
+    const entry = metric.entries[metric.entries.length - 1];
+    window._LCP3 = entry.size;
+  });
+};
diff --git a/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/subject.js b/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/subject.js
index 838e6e864414..d57faa5bc8b1 100644
--- a/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/subject.js
+++ b/dev-packages/browser-integration-tests/suites/tracing/metrics/handlers-lcp/subject.js
@@ -1,18 +1 @@
-import { addLcpInstrumentationHandler } from '@sentry/browser-utils';
-
-addLcpInstrumentationHandler(({ metric }) => {
-  const entry = metric.entries[metric.entries.length - 1];
-  window._LCP = entry.size;
-});
-
-addLcpInstrumentationHandler(({ metric }) => {
-  const entry = metric.entries[metric.entries.length - 1];
-  window._LCP2 = entry.size;
-});
-
-window.ADD_HANDLER = () => {
-  addLcpInstrumentationHandler(({ metric }) => {
-    const entry = metric.entries[metric.entries.length - 1];
-    window._LCP3 = entry.size;
-  });
-};
+// The handlers live in `init.js`, see there.