diff --git a/package.json b/package.json
index 13bdd1caecd06..ea306196a02e5 100644
--- a/package.json
+++ b/package.json
@@ -30,11 +30,11 @@
     "test": "c8 --check-coverage --lines 93 run-s test:chrome:* test:firefox",
     "test:types": "tsd",
     "test:install": "scripts/test-install.sh",
-    "test:firefox": "cross-env PUPPETEER_PRODUCT=firefox MOZ_WEBRENDER=0 mocha",
+    "test:firefox": "cross-env PUPPETEER_PRODUCT=firefox MOZ_WEBRENDER=0 PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT=20000 mocha",
     "test:chrome": "run-s test:chrome:*",
-    "test:chrome:headless": "cross-env HEADLESS=true mocha",
-    "test:chrome:headless-chrome": "cross-env HEADLESS=chrome mocha",
-    "test:chrome:headful": "cross-env HEADLESS=false mocha",
+    "test:chrome:headless": "cross-env HEADLESS=true PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT=20000 mocha",
+    "test:chrome:headless-chrome": "cross-env HEADLESS=chrome PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT=20000 mocha",
+    "test:chrome:headful": "cross-env HEADLESS=false PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT=20000 mocha",
     "prepublishOnly": "npm run build",
     "prepare": "node typescript-if-required.js && husky install",
     "lint": "run-s lint:prettier lint:eslint",
diff --git a/src/common/FrameManager.ts b/src/common/FrameManager.ts
index 182dc1a17a212..e027cc62cb3c0 100644
--- a/src/common/FrameManager.ts
+++ b/src/common/FrameManager.ts
@@ -17,7 +17,7 @@
 import {Protocol} from 'devtools-protocol';
 import {assert} from '../util/assert.js';
 import {
-  createDeferredPromiseWithTimer,
+  createDebuggableDeferredPromise,
   DeferredPromise,
 } from '../util/DeferredPromise.js';
 import {isErrorLike} from '../util/ErrorLike.js';
@@ -150,7 +150,7 @@ export class FrameManager extends EventEmitter {
       if (!this.#framesPendingTargetInit.has(targetId)) {
         this.#framesPendingTargetInit.set(
           targetId,
-          createDeferredPromiseWithTimer(
+          createDebuggableDeferredPromise(
             `Waiting for target frame ${targetId} failed`
           )
         );
@@ -318,7 +318,7 @@ export class FrameManager extends EventEmitter {
       if (!this.#framesPendingAttachment.has(frameId)) {
         this.#framesPendingAttachment.set(
           frameId,
-          createDeferredPromiseWithTimer(
+          createDebuggableDeferredPromise(
             `Waiting for frame ${frameId} to attach failed`
           )
         );
diff --git a/src/common/NetworkManager.ts b/src/common/NetworkManager.ts
index f128892f4b1e6..4aaacd4c9faeb 100644
--- a/src/common/NetworkManager.ts
+++ b/src/common/NetworkManager.ts
@@ -24,7 +24,7 @@ import {HTTPResponse} from './HTTPResponse.js';
 import {FetchRequestId, NetworkEventManager} from './NetworkEventManager.js';
 import {debugError, isString} from './util.js';
 import {
-  createDeferredPromiseWithTimer,
+  createDebuggableDeferredPromise,
   DeferredPromise,
 } from '../util/DeferredPromise.js';
 
@@ -144,9 +144,8 @@ export class NetworkManager extends EventEmitter {
     if (this.#deferredInitPromise) {
       return this.#deferredInitPromise;
     }
-    this.#deferredInitPromise = createDeferredPromiseWithTimer<void>(
-      'NetworkManager initialization timed out',
-      30000
+    this.#deferredInitPromise = createDebuggableDeferredPromise<void>(
+      'NetworkManager initialization timed out'
     );
     const init = Promise.all([
       this.#ignoreHTTPSErrors
diff --git a/src/environment.ts b/src/environment.ts
index 5ceca84a0e333..876eac8f15db1 100644
--- a/src/environment.ts
+++ b/src/environment.ts
@@ -18,3 +18,12 @@
  * @internal
  */
 export const isNode = !!(typeof process !== 'undefined' && process.version);
+
+/**
+ * @internal
+ */
+export const deferredPromiseDebugTimeout =
+  typeof process !== 'undefined' &&
+  typeof process.env['PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT'] !== 'undefined'
+    ? Number(process.env['PUPPETEER_DEFERRED_PROMISE_DEBUG_TIMEOUT'])
+    : -1;
diff --git a/src/util/DeferredPromise.ts b/src/util/DeferredPromise.ts
index cc8d7f154d115..a91f5d9672ce1 100644
--- a/src/util/DeferredPromise.ts
+++ b/src/util/DeferredPromise.ts
@@ -1,15 +1,16 @@
 import {TimeoutError} from '../common/Errors.js';
+import {deferredPromiseDebugTimeout} from '../environment.js';
 
 /**
  * @internal
  */
-
 export interface DeferredPromise<T> extends Promise<T> {
   finished: () => boolean;
   resolved: () => boolean;
   resolve: (_: T) => void;
   reject: (_: Error) => void;
 }
+
 /**
  * Creates an returns a promise along with the resolve/reject functions.
  *
@@ -18,7 +19,6 @@ export interface DeferredPromise<T> extends Promise<T> {
  *
  * @internal
  */
-
 export function createDeferredPromiseWithTimer<T>(
   timeoutMessage: string,
   timeout = 5000
@@ -54,12 +54,12 @@ export function createDeferredPromiseWithTimer<T>(
     },
   });
 }
+
 /**
  * Creates an returns a promise along with the resolve/reject functions.
  *
  * @internal
  */
-
 export function createDeferredPromise<T>(): DeferredPromise<T> {
   let isResolved = false;
   let isRejected = false;
@@ -86,3 +86,18 @@ export function createDeferredPromise<T>(): DeferredPromise<T> {
     },
   });
 }
+
+/**
+ * @internal
+ */
+export function createDebuggableDeferredPromise<T>(
+  timeoutMessage: string
+): DeferredPromise<T> {
+  if (deferredPromiseDebugTimeout > 0) {
+    return createDeferredPromiseWithTimer(
+      timeoutMessage,
+      deferredPromiseDebugTimeout
+    );
+  }
+  return createDeferredPromise();
+}