diff --git a/package-lock.json b/package-lock.json
index 655b04a07..4f4f74ad2 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -41,11 +41,11 @@
         "elliptic": "6.5.7",
         "escape-goat": "3.0.0",
         "evt": "1.10.1",
-        "express": "^4.21.1",
+        "express": "4.21.1",
         "fastify": "4.28.1",
         "fastify-metrics": "11.0.0",
         "getopts": "2.3.0",
-        "http-proxy-middleware": "^2.0.7",
+        "http-proxy-middleware": "2.0.7",
         "jsonc-parser": "3.0.0",
         "jsonrpc-lite": "2.2.0",
         "lru-cache": "6.0.0",
@@ -69,6 +69,7 @@
         "strict-event-emitter-types": "2.0.0",
         "tiny-secp256k1": "2.2.1",
         "ts-unused-exports": "7.0.3",
+        "undici": "6.21.0",
         "uuid": "8.3.2",
         "ws": "7.5.10",
         "zone-file": "2.0.0-beta.3"
@@ -171,6 +172,19 @@
         "undici": "^5.25.4"
       }
     },
+    "node_modules/@actions/http-client/node_modules/undici": {
+      "version": "5.28.4",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.4.tgz",
+      "integrity": "sha512-72RFADWFqKmUb2hmmvNODKL3p9hcB6Gt2DOQMis1SEBaV6a4MH8soBvzg+95CYhCKPFedut2JY9bMfrDl9D23g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@fastify/busboy": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=14.0"
+      }
+    },
     "node_modules/@actions/io": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/@actions/io/-/io-1.1.1.tgz",
@@ -1255,6 +1269,18 @@
         "undici": "^5.19.1"
       }
     },
+    "node_modules/@fastify/reply-from/node_modules/undici": {
+      "version": "5.28.4",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.4.tgz",
+      "integrity": "sha512-72RFADWFqKmUb2hmmvNODKL3p9hcB6Gt2DOQMis1SEBaV6a4MH8soBvzg+95CYhCKPFedut2JY9bMfrDl9D23g==",
+      "license": "MIT",
+      "dependencies": {
+        "@fastify/busboy": "^2.0.0"
+      },
+      "engines": {
+        "node": ">=14.0"
+      }
+    },
     "node_modules/@fastify/swagger": {
       "version": "8.15.0",
       "resolved": "https://registry.npmjs.org/@fastify/swagger/-/swagger-8.15.0.tgz",
@@ -16928,14 +16954,12 @@
       "dev": true
     },
     "node_modules/undici": {
-      "version": "5.28.4",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-5.28.4.tgz",
-      "integrity": "sha512-72RFADWFqKmUb2hmmvNODKL3p9hcB6Gt2DOQMis1SEBaV6a4MH8soBvzg+95CYhCKPFedut2JY9bMfrDl9D23g==",
-      "dependencies": {
-        "@fastify/busboy": "^2.0.0"
-      },
+      "version": "6.21.0",
+      "resolved": "https://registry.npmjs.org/undici/-/undici-6.21.0.tgz",
+      "integrity": "sha512-BUgJXc752Kou3oOIuU1i+yZZypyZRqNPW0vqoMPl8VaoalSfeR0D8/t4iAS3yirs79SSMTxTag+ZC86uswv+Cw==",
+      "license": "MIT",
       "engines": {
-        "node": ">=14.0"
+        "node": ">=18.17"
       }
     },
     "node_modules/undici-types": {
diff --git a/package.json b/package.json
index 89bd0212d..06bbae90d 100644
--- a/package.json
+++ b/package.json
@@ -147,6 +147,7 @@
     "strict-event-emitter-types": "2.0.0",
     "tiny-secp256k1": "2.2.1",
     "ts-unused-exports": "7.0.3",
+    "undici": "6.21.0",
     "uuid": "8.3.2",
     "ws": "7.5.10",
     "zone-file": "2.0.0-beta.3"
diff --git a/src/api/routes/core-node-rpc-proxy.ts b/src/api/routes/core-node-rpc-proxy.ts
index d1e40999c..37b3e46bf 100644
--- a/src/api/routes/core-node-rpc-proxy.ts
+++ b/src/api/routes/core-node-rpc-proxy.ts
@@ -152,9 +152,7 @@ export const CoreNodeRpcProxyRouter: FastifyPluginAsync<
     upstream: `http://${stacksNodeRpcEndpoint}`,
     rewritePrefix: '/v2',
     http2: false,
-    // Use the `node:http` agent for requests https://github.com/fastify/fastify-reply-from?tab=readme-ov-file#globalagent
     globalAgent: true,
-    http: {},
     preValidation: async (req, reply) => {
       if (getReqUrl(req).pathname !== '/v2/transactions') {
         return;
diff --git a/tests/api/v2-proxy.test.ts b/tests/api/v2-proxy.test.ts
index f96e9e20e..8f97e87b0 100644
--- a/tests/api/v2-proxy.test.ts
+++ b/tests/api/v2-proxy.test.ts
@@ -9,6 +9,7 @@ import * as nock from 'nock';
 import { DbBlock } from '../../src/datastore/common';
 import { PgWriteStore } from '../../src/datastore/pg-write-store';
 import { migrate } from '../utils/test-helpers';
+import { MockAgent, setGlobalDispatcher, getGlobalDispatcher } from 'undici';
 
 describe('v2-proxy tests', () => {
   let db: PgWriteStore;
@@ -39,6 +40,12 @@ describe('v2-proxy tests', () => {
         );
         return [, () => restoreEnvVars()] as const;
       },
+      () => {
+        const agent = new MockAgent();
+        const originalAgent = getGlobalDispatcher();
+        setGlobalDispatcher(agent);
+        return [agent, () => setGlobalDispatcher(originalAgent)] as const;
+      },
       async () => {
         const apiServer = await startApiServer({
           datastore: db,
@@ -46,7 +53,7 @@ describe('v2-proxy tests', () => {
         });
         return [apiServer, apiServer.terminate] as const;
       },
-      async (_, api) => {
+      async (_, mockAgent, api) => {
         const primaryStubbedResponse = {
           cost_scalar_change_by_byte: 0.00476837158203125,
           estimated_cost: {
@@ -77,12 +84,17 @@ describe('v2-proxy tests', () => {
           transaction_payload:
             '021af942874ce525e87f21bbe8c121b12fac831d02f4086765742d696e666f0b7570646174652d696e666f00000000',
         };
-        nock(`http://${primaryProxyEndpoint}`)
-          .post('/v2/fees/transaction')
-          .once()
+
+        mockAgent
+          .get(`http://${primaryProxyEndpoint}`)
+          .intercept({
+            path: '/v2/fees/transaction',
+            method: 'POST',
+          })
           .reply(200, JSON.stringify(primaryStubbedResponse), {
-            'Content-Type': 'application/json',
+            headers: { 'Content-Type': 'application/json' },
           });
+
         const postTxReq = await supertest(api.server)
           .post(`/v2/fees/transaction`)
           .set('Content-Type', 'application/json')