diff --git a/shared/constants/transaction.ts b/shared/constants/transaction.ts
index 38311de3be76..ac4bb77b070a 100644
--- a/shared/constants/transaction.ts
+++ b/shared/constants/transaction.ts
@@ -199,3 +199,10 @@ export enum TokenStandard {
   /** Not a token, but rather the base asset of the selected chain. */
   none = 'NONE',
 }
+
+/**
+ * The hostname used for Ethereum Mainnet transaction simulations, and for
+ * retrieving metadata for transaction simulation supported networks.
+ */
+export const TX_SENTINEL_URL =
+  'https://tx-sentinel-ethereum-mainnet.api.cx.metamask.io';
diff --git a/test/e2e/mock-e2e.js b/test/e2e/mock-e2e.js
index d6d19d972d3b..e938b5604a82 100644
--- a/test/e2e/mock-e2e.js
+++ b/test/e2e/mock-e2e.js
@@ -16,6 +16,7 @@ const {
   SWAPS_API_V2_BASE_URL,
   TOKEN_API_BASE_URL,
 } = require('../../shared/constants/swaps');
+const { TX_SENTINEL_URL } = require('../../shared/constants/transaction');
 const { SECURITY_ALERTS_PROD_API_BASE_URL } = require('./tests/ppom/constants');
 const {
   DEFAULT_FEATURE_FLAGS_RESPONSE: BRIDGE_DEFAULT_FEATURE_FLAGS_RESPONSE,
@@ -314,6 +315,21 @@ async function setupMocking(
       };
     });
 
+  // This endpoint returns metadata for "transaction simulation" supported networks.
+  await server.forGet(`${TX_SENTINEL_URL}/networks`).thenJson(200, {
+    1: {
+      name: 'Mainnet',
+      group: 'ethereum',
+      chainID: 1,
+      nativeCurrency: { name: 'ETH', symbol: 'ETH', decimals: 18 },
+      network: 'ethereum-mainnet',
+      explorer: 'https://etherscan.io',
+      confirmations: true,
+      smartTransactions: true,
+      hidden: false,
+    },
+  });
+
   await server
     .forGet(`${SWAPS_API_V2_BASE_URL}/featureFlags`)
     .thenCallback(() => {
diff --git a/test/e2e/tests/simulation-details/simulation-details.spec.ts b/test/e2e/tests/simulation-details/simulation-details.spec.ts
index 20475a945dde..c69a2f798b3d 100644
--- a/test/e2e/tests/simulation-details/simulation-details.spec.ts
+++ b/test/e2e/tests/simulation-details/simulation-details.spec.ts
@@ -1,6 +1,7 @@
 import { hexToNumber } from '@metamask/utils';
 import { Mockttp, MockttpServer } from 'mockttp';
 import { CHAIN_IDS } from '../../../../shared/constants/network';
+import { TX_SENTINEL_URL } from '../../../../shared/constants/transaction';
 import FixtureBuilder from '../../fixture-builder';
 import {
   createDappTransaction,
@@ -43,15 +44,6 @@ import {
 } from './mock-request-send-eth';
 import { MockRequestResponse } from './types';
 
-const TX_SENTINEL_URL =
-  'https://tx-sentinel-ethereum-mainnet.api.cx.metamask.io/';
-
-const mockNetworkRequest = async (mockServer: Mockttp) => {
-  await mockServer.forGet(`${TX_SENTINEL_URL}/networks`).thenJson(200, {
-    '1': { name: 'Mainnet', confirmations: true },
-  });
-};
-
 async function withFixturesForSimulationDetails(
   {
     title,
@@ -64,17 +56,13 @@ async function withFixturesForSimulationDetails(
   },
   test: (args: Pick<Fixtures, 'driver' | 'mockServer'>) => Promise<void>,
 ) {
-  const testSpecificMock = async (mockServer: MockttpServer) => {
-    await mockNetworkRequest(mockServer);
-    await mockRequests(mockServer);
-  };
   await withFixtures(
     {
       fixtures: new FixtureBuilder({ inputChainId })
         .withPermissionControllerConnectedToTestDapp()
         .build(),
       title,
-      testSpecificMock,
+      testSpecificMock: mockRequests,
       dapp: true,
       localNodeOptions: {
         hardfork: 'london',