diff --git a/dev-packages/node-core-integration-tests/suites/anr/app-path.mjs b/dev-packages/node-core-integration-tests/suites/anr/app-path.mjs
index 28f245851b01..1c5f141021a8 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/app-path.mjs
+++ b/dev-packages/node-core-integration-tests/suites/anr/app-path.mjs
@@ -4,6 +4,7 @@ import * as crypto from 'crypto';
 import * as path from 'path';
 import * as url from 'url';
 import { setupOtel } from '../../utils/setupOtel.js';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -32,6 +33,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/basic-multiple.mjs b/dev-packages/node-core-integration-tests/suites/anr/basic-multiple.mjs
index 1caf96d3abdb..6b0e1de340dd 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/basic-multiple.mjs
+++ b/dev-packages/node-core-integration-tests/suites/anr/basic-multiple.mjs
@@ -2,6 +2,7 @@ import * as Sentry from '@sentry/node-core';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
 import { setupOtel } from '../../utils/setupOtel.js';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -28,10 +29,11 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
 
-setTimeout(() => {
-  longWork();
-}, 4000);
+  // Second blocking event for maxAnrEvents test
+  setTimeout(() => {
+    longWork();
+  }, 2000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/basic-session.js b/dev-packages/node-core-integration-tests/suites/anr/basic-session.js
index e89a65e79ad2..229f4eb28d5b 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/basic-session.js
+++ b/dev-packages/node-core-integration-tests/suites/anr/basic-session.js
@@ -3,6 +3,7 @@ const assert = require('assert');
 
 const Sentry = require('@sentry/node-core');
 const { setupOtel } = require('../../utils/setupOtel.js');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 setTimeout(() => {
   process.exit();
@@ -27,6 +28,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/basic.js b/dev-packages/node-core-integration-tests/suites/anr/basic.js
index 9010fb296c48..d02ed4f254f1 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/basic.js
+++ b/dev-packages/node-core-integration-tests/suites/anr/basic.js
@@ -3,6 +3,7 @@ const assert = require('assert');
 
 const Sentry = require('@sentry/node-core');
 const { setupOtel } = require('../../utils/setupOtel.js');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -29,6 +30,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/basic.mjs b/dev-packages/node-core-integration-tests/suites/anr/basic.mjs
index 109a201ecb98..71525c7e9ebe 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/basic.mjs
+++ b/dev-packages/node-core-integration-tests/suites/anr/basic.mjs
@@ -2,6 +2,7 @@ import * as Sentry from '@sentry/node-core';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
 import { setupOtel } from '../../utils/setupOtel.js';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -28,11 +29,11 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
 
-// Ensure we only send one event even with multiple blocking events
-setTimeout(() => {
-  longWork();
-}, 4000);
+  // Ensure we only send one event even with multiple blocking events
+  setTimeout(() => {
+    longWork();
+  }, 2000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/forked.js b/dev-packages/node-core-integration-tests/suites/anr/forked.js
index 2fd7a0678e8d..5dd6c93e82ef 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/forked.js
+++ b/dev-packages/node-core-integration-tests/suites/anr/forked.js
@@ -3,6 +3,7 @@ const assert = require('assert');
 
 const Sentry = require('@sentry/node-core');
 const { setupOtel } = require('../../utils/setupOtel.js');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 setTimeout(() => {
   process.exit();
@@ -28,6 +29,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-core-integration-tests/suites/anr/indefinite.mjs b/dev-packages/node-core-integration-tests/suites/anr/indefinite.mjs
index db9217ec34b2..0b8d33757e90 100644
--- a/dev-packages/node-core-integration-tests/suites/anr/indefinite.mjs
+++ b/dev-packages/node-core-integration-tests/suites/anr/indefinite.mjs
@@ -2,6 +2,7 @@ import * as Sentry from '@sentry/node-core';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
 import { setupOtel } from '../../utils/setupOtel.js';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 setTimeout(() => {
   process.exit();
@@ -27,6 +28,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/app-path.mjs b/dev-packages/node-integration-tests/suites/anr/app-path.mjs
index 5ace9ebbb3e8..e0a13f7e6869 100644
--- a/dev-packages/node-integration-tests/suites/anr/app-path.mjs
+++ b/dev-packages/node-integration-tests/suites/anr/app-path.mjs
@@ -3,6 +3,7 @@ import * as assert from 'assert';
 import * as crypto from 'crypto';
 import * as path from 'path';
 import * as url from 'url';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -29,6 +30,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/basic-multiple.mjs b/dev-packages/node-integration-tests/suites/anr/basic-multiple.mjs
index d24e5d9f20d9..a8b0aa0b7c5d 100644
--- a/dev-packages/node-integration-tests/suites/anr/basic-multiple.mjs
+++ b/dev-packages/node-integration-tests/suites/anr/basic-multiple.mjs
@@ -1,6 +1,7 @@
 import * as Sentry from '@sentry/node';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -25,10 +26,11 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
 
-setTimeout(() => {
-  longWork();
-}, 4000);
+  // Second blocking event for maxAnrEvents test
+  setTimeout(() => {
+    longWork();
+  }, 2000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/basic-session.js b/dev-packages/node-integration-tests/suites/anr/basic-session.js
index 7971d547c884..8658c465adc9 100644
--- a/dev-packages/node-integration-tests/suites/anr/basic-session.js
+++ b/dev-packages/node-integration-tests/suites/anr/basic-session.js
@@ -2,6 +2,7 @@ const crypto = require('crypto');
 const assert = require('assert');
 
 const Sentry = require('@sentry/node');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 setTimeout(() => {
   process.exit();
@@ -24,6 +25,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/basic.js b/dev-packages/node-integration-tests/suites/anr/basic.js
index 430058200b8f..61b394c630e2 100644
--- a/dev-packages/node-integration-tests/suites/anr/basic.js
+++ b/dev-packages/node-integration-tests/suites/anr/basic.js
@@ -2,6 +2,7 @@ const crypto = require('crypto');
 const assert = require('assert');
 
 const Sentry = require('@sentry/node');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -26,6 +27,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/basic.mjs b/dev-packages/node-integration-tests/suites/anr/basic.mjs
index 19b766c1e0e4..20737c93c5f2 100644
--- a/dev-packages/node-integration-tests/suites/anr/basic.mjs
+++ b/dev-packages/node-integration-tests/suites/anr/basic.mjs
@@ -1,6 +1,7 @@
 import * as Sentry from '@sentry/node';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 global._sentryDebugIds = { [new Error().stack]: 'aaaaaaaa-aaaa-4aaa-aaaa-aaaaaaaaaa' };
 
@@ -25,11 +26,11 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
 
-// Ensure we only send one event even with multiple blocking events
-setTimeout(() => {
-  longWork();
-}, 4000);
+  // Ensure we only send one event even with multiple blocking events
+  setTimeout(() => {
+    longWork();
+  }, 2000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/forked.js b/dev-packages/node-integration-tests/suites/anr/forked.js
index e0e120f41256..1abed46c7b68 100644
--- a/dev-packages/node-integration-tests/suites/anr/forked.js
+++ b/dev-packages/node-integration-tests/suites/anr/forked.js
@@ -2,6 +2,7 @@ const crypto = require('crypto');
 const assert = require('assert');
 
 const Sentry = require('@sentry/node');
+const { waitForDebuggerReady } = require('@sentry-internal/test-utils');
 
 setTimeout(() => {
   process.exit();
@@ -25,6 +26,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/node-integration-tests/suites/anr/indefinite.mjs b/dev-packages/node-integration-tests/suites/anr/indefinite.mjs
index 927e4e5fc4ad..849e35903e14 100644
--- a/dev-packages/node-integration-tests/suites/anr/indefinite.mjs
+++ b/dev-packages/node-integration-tests/suites/anr/indefinite.mjs
@@ -1,6 +1,7 @@
 import * as Sentry from '@sentry/node';
 import * as assert from 'assert';
 import * as crypto from 'crypto';
+import { waitForDebuggerReady } from '@sentry-internal/test-utils';
 
 setTimeout(() => {
   process.exit();
@@ -24,6 +25,6 @@ function longWork() {
   }
 }
 
-setTimeout(() => {
+waitForDebuggerReady(() => {
   longWork();
-}, 1000);
+});
diff --git a/dev-packages/test-utils/src/anr.ts b/dev-packages/test-utils/src/anr.ts
new file mode 100644
index 000000000000..7ad8cb097f30
--- /dev/null
+++ b/dev-packages/test-utils/src/anr.ts
@@ -0,0 +1,19 @@
+import * as inspector from 'inspector';
+
+/**
+ * Waits for the ANR worker's debugger to be fully ready before executing callback.
+ *
+ * The ANR worker creates an InspectorSession and connects to the main thread's debugger.
+ * We poll inspector.url() to detect when the debugger is active, then wait 200ms for the
+ * async session setup to complete.
+ */
+export function waitForDebuggerReady(cb: () => void): void {
+  const check = (): void => {
+    if (inspector.url()) {
+      setTimeout(cb, 200);
+    } else {
+      setImmediate(check);
+    }
+  };
+  setImmediate(check);
+}
diff --git a/dev-packages/test-utils/src/index.ts b/dev-packages/test-utils/src/index.ts
index c47f46fcde5e..aaf4cc1d886a 100644
--- a/dev-packages/test-utils/src/index.ts
+++ b/dev-packages/test-utils/src/index.ts
@@ -26,3 +26,5 @@ export type { CDPClientOptions } from './cdp-client';
 
 export { MemoryProfiler } from './memory-profiler';
 export type { MemoryProfilerOptions, SnapshotStats, SnapshotComparisonResult } from './memory-profiler';
+
+export { waitForDebuggerReady } from './anr';