diff --git a/doc/api/http.md b/doc/api/http.md
index 71203056b359f3..8851ae8d6e4893 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -262,6 +262,10 @@ terminates them.
 ### `agent.freeSockets`
 <!-- YAML
 added: v0.11.4
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/36409
+    description: The property now has a `null` prototype.
 -->
 
 * {Object}
@@ -328,6 +332,10 @@ can have open. Unlike `maxSockets`, this parameter applies across all origins.
 ### `agent.requests`
 <!-- YAML
 added: v0.5.9
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/36409
+    description: The property now has a `null` prototype.
 -->
 
 * {Object}
@@ -338,6 +346,10 @@ sockets. Do not modify.
 ### `agent.sockets`
 <!-- YAML
 added: v0.3.6
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/36409
+    description: The property now has a `null` prototype.
 -->
 
 * {Object}
diff --git a/lib/_http_agent.js b/lib/_http_agent.js
index 6f6a0920fd8c04..10638fe69ed124 100644
--- a/lib/_http_agent.js
+++ b/lib/_http_agent.js
@@ -23,6 +23,7 @@
 
 const {
   NumberIsNaN,
+  ObjectCreate,
   ObjectKeys,
   ObjectSetPrototypeOf,
   ObjectValues,
@@ -83,13 +84,13 @@ function Agent(options) {
   this.defaultPort = 80;
   this.protocol = 'http:';
 
-  this.options = { ...options };
+  this.options = { __proto__: null, ...options };
 
   // Don't confuse net and make it think that we're connecting to a pipe
   this.options.path = null;
-  this.requests = {};
-  this.sockets = {};
-  this.freeSockets = {};
+  this.requests = ObjectCreate(null);
+  this.sockets = ObjectCreate(null);
+  this.freeSockets = ObjectCreate(null);
   this.keepAliveMsecs = this.options.keepAliveMsecs || 1000;
   this.keepAlive = this.options.keepAlive || false;
   this.maxSockets = this.options.maxSockets || Agent.defaultMaxSockets;
@@ -227,13 +228,14 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
   // Legacy API: addRequest(req, host, port, localAddress)
   if (typeof options === 'string') {
     options = {
+      __proto__: null,
       host: options,
       port,
       localAddress
     };
   }
 
-  options = { ...options, ...this.options };
+  options = { __proto__: null, ...options, ...this.options };
   if (options.socketPath)
     options.path = options.socketPath;
 
@@ -294,7 +296,7 @@ Agent.prototype.addRequest = function addRequest(req, options, port/* legacy */,
 };
 
 Agent.prototype.createSocket = function createSocket(req, options, cb) {
-  options = { ...options, ...this.options };
+  options = { __proto__: null, ...options, ...this.options };
   if (options.socketPath)
     options.path = options.socketPath;
 
@@ -435,7 +437,7 @@ Agent.prototype.removeSocket = function removeSocket(s, options) {
     // There might be older requests in a different origin, but
     // if the origin which releases the socket has pending requests
     // that will be prioritized.
-    for (const prop in this.requests) {
+    for (const prop of ObjectKeys(this.requests)) {
       // Check whether this specific origin is already at maxSockets
       if (this.sockets[prop] && this.sockets[prop].length) break;
       debug('removeSocket, have a request with different origin,' +
diff --git a/test/parallel/test-http-client-agent.js b/test/parallel/test-http-client-agent.js
index 3ae906f09c92ae..77616edd99d2fb 100644
--- a/test/parallel/test-http-client-agent.js
+++ b/test/parallel/test-http-client-agent.js
@@ -46,8 +46,8 @@ server.listen(0, common.mustCall(() => {
 }));
 
 const countdown = new Countdown(max, () => {
-  assert(!http.globalAgent.sockets.hasOwnProperty(name));
-  assert(!http.globalAgent.requests.hasOwnProperty(name));
+  assert(!(name in http.globalAgent.sockets));
+  assert(!(name in http.globalAgent.requests));
   server.close();
 });
 
diff --git a/test/parallel/test-http-client-override-global-agent.js b/test/parallel/test-http-client-override-global-agent.js
index 0efaded5e419b0..f8b2928940e188 100644
--- a/test/parallel/test-http-client-override-global-agent.js
+++ b/test/parallel/test-http-client-override-global-agent.js
@@ -14,7 +14,7 @@ server.listen(0, common.mustCall(() => {
   http.globalAgent = agent;
 
   makeRequest();
-  assert(agent.sockets.hasOwnProperty(name)); // Agent has indeed been used
+  assert(name in agent.sockets); // Agent has indeed been used
 }));
 
 function makeRequest() {
diff --git a/test/parallel/test-http-connect-req-res.js b/test/parallel/test-http-connect-req-res.js
index cd6e55e0898c66..dfb83a41aa6236 100644
--- a/test/parallel/test-http-connect-req-res.js
+++ b/test/parallel/test-http-connect-req-res.js
@@ -43,8 +43,8 @@ server.listen(0, common.mustCall(function() {
 
     // Make sure this request got removed from the pool.
     const name = `localhost:${server.address().port}`;
-    assert(!http.globalAgent.sockets.hasOwnProperty(name));
-    assert(!http.globalAgent.requests.hasOwnProperty(name));
+    assert(!(name in http.globalAgent.sockets));
+    assert(!(name in http.globalAgent.requests));
 
     // Make sure this socket has detached.
     assert(!socket.ondata);
diff --git a/test/parallel/test-http-connect.js b/test/parallel/test-http-connect.js
index 47fd7316d0cf1d..b6053ba9d45187 100644
--- a/test/parallel/test-http-connect.js
+++ b/test/parallel/test-http-connect.js
@@ -70,8 +70,8 @@ server.listen(0, common.mustCall(() => {
   req.on('connect', common.mustCall((res, socket, firstBodyChunk) => {
     // Make sure this request got removed from the pool.
     const name = `localhost:${server.address().port}`;
-    assert(!http.globalAgent.sockets.hasOwnProperty(name));
-    assert(!http.globalAgent.requests.hasOwnProperty(name));
+    assert(!(name in http.globalAgent.sockets));
+    assert(!(name in http.globalAgent.requests));
 
     // Make sure this socket has detached.
     assert(!socket.ondata);
diff --git a/test/parallel/test-http-keep-alive.js b/test/parallel/test-http-keep-alive.js
index 42d534e8e6b459..bd075230d16db1 100644
--- a/test/parallel/test-http-keep-alive.js
+++ b/test/parallel/test-http-keep-alive.js
@@ -59,7 +59,7 @@ server.listen(0, common.mustCall(function() {
   }, common.mustCall((response) => {
     response.on('end', common.mustCall(() => {
       assert.strictEqual(agent.sockets[name].length, 1);
-      assert(!agent.requests.hasOwnProperty(name));
+      assert(!(name in agent.requests));
       server.close();
     }));
     response.resume();
@@ -67,6 +67,6 @@ server.listen(0, common.mustCall(function() {
 }));
 
 process.on('exit', () => {
-  assert(!agent.sockets.hasOwnProperty(name));
-  assert(!agent.requests.hasOwnProperty(name));
+  assert(!(name in agent.sockets));
+  assert(!(name in agent.requests));
 });
diff --git a/test/parallel/test-http-upgrade-agent.js b/test/parallel/test-http-upgrade-agent.js
index cb33edc32e0139..28498819490b4f 100644
--- a/test/parallel/test-http-upgrade-agent.js
+++ b/test/parallel/test-http-upgrade-agent.js
@@ -78,7 +78,7 @@ server.listen(0, '127.0.0.1', common.mustCall(function() {
     assert.deepStrictEqual(expectedHeaders, res.headers);
 
     // Make sure this request got removed from the pool.
-    assert(!http.globalAgent.sockets.hasOwnProperty(name));
+    assert(!(name in http.globalAgent.sockets));
 
     req.on('close', common.mustCall(function() {
       socket.end();
diff --git a/test/parallel/test-https-client-override-global-agent.js b/test/parallel/test-https-client-override-global-agent.js
index a4bb2732756b2b..8774e77bb95d37 100644
--- a/test/parallel/test-https-client-override-global-agent.js
+++ b/test/parallel/test-https-client-override-global-agent.js
@@ -25,7 +25,7 @@ server.listen(0, common.mustCall(() => {
   https.globalAgent = agent;
 
   makeRequest();
-  assert(agent.sockets.hasOwnProperty(name)); // Agent has indeed been used
+  assert(name in agent.sockets); // Agent has indeed been used
 }));
 
 function makeRequest() {