diff --git a/packages/playwright-core/src/server/chromium/crNetworkManager.ts b/packages/playwright-core/src/server/chromium/crNetworkManager.ts
index b78dd4084e..6411457a32 100644
--- a/packages/playwright-core/src/server/chromium/crNetworkManager.ts
+++ b/packages/playwright-core/src/server/chromium/crNetworkManager.ts
@@ -317,7 +317,7 @@ export class CRNetworkManager {
       requestPausedSessionInfo!.session._sendMayFail('Fetch.fulfillRequest', {
         requestId: requestPausedEvent.requestId,
         responseCode: 204,
-        responsePhrase: network.STATUS_TEXTS['204'],
+        responsePhrase: network.statusText(204),
         responseHeaders,
         body: '',
       });
@@ -622,7 +622,7 @@ class RouteImpl implements network.RouteDelegate {
       await this._session.send('Fetch.fulfillRequest', {
         requestId: this._interceptionId!,
         responseCode: response.status,
-        responsePhrase: network.STATUS_TEXTS[String(response.status)],
+        responsePhrase: network.statusText(response.status),
         responseHeaders,
         body,
       });
diff --git a/packages/playwright-core/src/server/firefox/ffNetworkManager.ts b/packages/playwright-core/src/server/firefox/ffNetworkManager.ts
index 081a1c9480..266f5bcb83 100644
--- a/packages/playwright-core/src/server/firefox/ffNetworkManager.ts
+++ b/packages/playwright-core/src/server/firefox/ffNetworkManager.ts
@@ -242,7 +242,7 @@ class FFRouteImpl implements network.RouteDelegate {
     await this._session.sendMayFail('Network.fulfillInterceptedRequest', {
       requestId: this._request._id,
       status: response.status,
-      statusText: network.STATUS_TEXTS[String(response.status)] || '',
+      statusText: network.statusText(response.status),
       headers: response.headers,
       base64body,
     });
diff --git a/packages/playwright-core/src/server/network.ts b/packages/playwright-core/src/server/network.ts
index 83b0093a38..fd62e1751b 100644
--- a/packages/playwright-core/src/server/network.ts
+++ b/packages/playwright-core/src/server/network.ts
@@ -616,7 +616,7 @@ export interface RouteDelegate {
 }
 
 // List taken from https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml with extra 306 and 418 codes.
-export const STATUS_TEXTS: { [status: string]: string } = {
+const STATUS_TEXTS: { [status: string]: string } = {
   '100': 'Continue',
   '101': 'Switching Protocols',
   '102': 'Processing',
@@ -682,6 +682,10 @@ export const STATUS_TEXTS: { [status: string]: string } = {
   '511': 'Network Authentication Required',
 };
 
+export function statusText(status: number): string {
+  return STATUS_TEXTS[String(status)] || 'Unknown';
+}
+
 export function singleHeader(name: string, value: string): HeadersArray {
   return [{ name, value }];
 }
diff --git a/packages/playwright-core/src/server/webkit/wkInterceptableRequest.ts b/packages/playwright-core/src/server/webkit/wkInterceptableRequest.ts
index 5218420480..f3c669dfc7 100644
--- a/packages/playwright-core/src/server/webkit/wkInterceptableRequest.ts
+++ b/packages/playwright-core/src/server/webkit/wkInterceptableRequest.ts
@@ -128,7 +128,7 @@ export class WKRouteImpl implements network.RouteDelegate {
     await this._session.sendMayFail('Network.interceptRequestWithResponse', {
       requestId: this._requestId,
       status: response.status,
-      statusText: network.STATUS_TEXTS[String(response.status)],
+      statusText: network.statusText(response.status),
       mimeType,
       headers,
       base64Encoded: response.isBase64,
diff --git a/tests/page/page-request-fulfill.spec.ts b/tests/page/page-request-fulfill.spec.ts
index 4a67b4353c..16f559b467 100644
--- a/tests/page/page-request-fulfill.spec.ts
+++ b/tests/page/page-request-fulfill.spec.ts
@@ -78,8 +78,9 @@ it('should work with status code 422', async ({ page, server }) => {
   expect(await page.evaluate(() => document.body.textContent)).toBe('Yo, page!');
 });
 
-it('should throw exception if status code is not supported', async ({ page, server, browserName }) => {
+it('should fulfill with unuassigned status codes', async ({ page, server, browserName }) => {
   it.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/28490' });
+  it.info().annotations.push({ type: 'issue', description: 'https://github.com/microsoft/playwright/issues/30773' });
   let fulfillPromiseCallback;
   const fulfillPromise = new Promise<Error|undefined>(f => fulfillPromiseCallback = f);
   await page.route('**/data.json', route => {
@@ -89,14 +90,14 @@ it('should throw exception if status code is not supported', async ({ page, serv
     }).catch(e => e));
   });
   await page.goto(server.EMPTY_PAGE);
-  page.evaluate(url => fetch(url), server.PREFIX + '/data.json').catch(() => {});
+  const response = await page.evaluate(async url => {
+    const { status, statusText } = await fetch(url);
+    return { status, statusText };
+  }, server.PREFIX + '/data.json');
   const error = await fulfillPromise;
-  if (browserName === 'chromium') {
-    expect(error).toBeTruthy();
-    expect(error.message).toContain(' Invalid http status code or phrase');
-  } else {
-    expect(error).toBe(undefined);
-  }
+  expect(error).toBe(undefined);
+  expect(response.status).toBe(430);
+  expect(response.statusText).toBe('Unknown');
 });
 
 it('should not throw if request was cancelled by the page', async ({ page, server }) => {