diff --git a/doc/api/http.md b/doc/api/http.md
index 92e56d6dc4b..d81c3a574bd 100644
--- a/doc/api/http.md
+++ b/doc/api/http.md
@@ -1917,6 +1917,9 @@ Found'`.
 <!-- YAML
 added: v0.1.13
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/31448
+    description: The `insecureHTTPParser` option is supported now.
   - version: v9.6.0, v8.12.0
     pr-url: https://github.com/nodejs/node/pull/15752
     description: The `options` argument is supported now.
@@ -1929,6 +1932,10 @@ changes:
   * `ServerResponse` {http.ServerResponse} Specifies the `ServerResponse` class
     to be used. Useful for extending the original `ServerResponse`. **Default:**
     `ServerResponse`.
+  * `insecureHTTPParser` {boolean} Use an insecure HTTP parser that accepts
+    invalid HTTP headers when `true`. Using the insecure parser should be
+    avoided. See [`--insecure-http-parser`][] for more information.
+    **Default:** `false`
 * `requestListener` {Function}
 
 * Returns: {http.Server}
@@ -2031,6 +2038,9 @@ Defaults to 8KB. Configurable using the [`--max-http-header-size`][] CLI option.
 <!-- YAML
 added: v0.3.6
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/31448
+    description: The `insecureHTTPParser` option is supported now.
   - version: v10.9.0
     pr-url: https://github.com/nodejs/node/pull/21616
     description: The `url` parameter can now be passed along with a separate
@@ -2064,6 +2074,10 @@ changes:
     request to. **Default:** `'localhost'`.
   * `hostname` {string} Alias for `host`. To support [`url.parse()`][],
     `hostname` will be used if both `host` and `hostname` are specified.
+  * `insecureHTTPParser` {boolean} Use an insecure HTTP parser that accepts
+    invalid HTTP headers when `true`. Using the insecure parser should be
+    avoided. See [`--insecure-http-parser`][] for more information.
+    **Default:** `false`
   * `localAddress` {string} Local interface to bind for network connections.
   * `lookup` {Function} Custom lookup function. **Default:** [`dns.lookup()`][].
   * `method` {string} A string specifying the HTTP request method. **Default:**
@@ -2216,6 +2230,7 @@ Setting the `timeout` option or using the `setTimeout()` function will
 not abort the request or do anything besides add a `'timeout'` event.
 
 [`--http-server-default-timeout`]: cli.html#cli_http_server_default_timeout_milliseconds
+[`--insecure-http-parser`]: cli.html#cli_insecure_http_parser
 [`--max-http-header-size`]: cli.html#cli_max_http_header_size_size
 [`'checkContinue'`]: #http_event_checkcontinue
 [`'request'`]: #http_event_request
diff --git a/lib/_http_client.js b/lib/_http_client.js
index 174700655f5..0e2e3b7c671 100644
--- a/lib/_http_client.js
+++ b/lib/_http_client.js
@@ -173,6 +173,14 @@ function ClientRequest(input, options, cb) {
     method = this.method = 'GET';
   }
 
+  const insecureHTTPParser = options.insecureHTTPParser;
+  if (insecureHTTPParser !== undefined &&
+      typeof insecureHTTPParser !== 'boolean') {
+    throw new ERR_INVALID_ARG_TYPE(
+      'insecureHTTPParser', 'boolean', insecureHTTPParser);
+  }
+  this.insecureHTTPParser = insecureHTTPParser;
+
   this.path = options.path || '/';
   if (cb) {
     this.once('response', cb);
@@ -656,7 +664,8 @@ function tickOnSocket(req, socket) {
   req.connection = socket;
   parser.initialize(HTTPParser.RESPONSE,
                     new HTTPClientAsyncResource('HTTPINCOMINGMESSAGE', req),
-                    isLenient());
+                    req.insecureHTTPParser === undefined ?
+                      isLenient() : req.insecureHTTPParser);
   parser.socket = socket;
   parser.outgoing = req;
   req.parser = parser;
diff --git a/lib/_http_server.js b/lib/_http_server.js
index 0638820a16c..ce2afd07622 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -329,6 +329,14 @@ function Server(options, requestListener) {
   this[kIncomingMessage] = options.IncomingMessage || IncomingMessage;
   this[kServerResponse] = options.ServerResponse || ServerResponse;
 
+  const insecureHTTPParser = options.insecureHTTPParser;
+  if (insecureHTTPParser !== undefined &&
+      typeof insecureHTTPParser !== 'boolean') {
+    throw new ERR_INVALID_ARG_TYPE(
+      'insecureHTTPParser', 'boolean', insecureHTTPParser);
+  }
+  this.insecureHTTPParser = insecureHTTPParser;
+
   net.Server.call(this, { allowHalfOpen: true });
 
   if (requestListener) {
@@ -387,7 +395,8 @@ function connectionListenerInternal(server, socket) {
   parser.initialize(
     HTTPParser.REQUEST,
     new HTTPServerAsyncResource('HTTPINCOMINGMESSAGE', socket),
-    isLenient(),
+    server.insecureHTTPParser === undefined ?
+      isLenient() : server.insecureHTTPParser,
   );
   parser.socket = socket;
 
diff --git a/test/parallel/test-http-insecure-parser-per-stream.js b/test/parallel/test-http-insecure-parser-per-stream.js
new file mode 100644
index 00000000000..d2b8ffe7087
--- /dev/null
+++ b/test/parallel/test-http-insecure-parser-per-stream.js
@@ -0,0 +1,82 @@
+'use strict';
+const common = require('../common');
+const assert = require('assert');
+const http = require('http');
+const MakeDuplexPair = require('../common/duplexpair');
+
+// Test that setting the `maxHeaderSize` option works on a per-stream-basis.
+
+// Test 1: The server sends an invalid header.
+{
+  const { clientSide, serverSide } = MakeDuplexPair();
+
+  const req = http.request({
+    createConnection: common.mustCall(() => clientSide),
+    insecureHTTPParser: true
+  }, common.mustCall((res) => {
+    assert.strictEqual(res.headers.hello, 'foo\x08foo');
+    res.resume();  // We don’t actually care about contents.
+    res.on('end', common.mustCall());
+  }));
+  req.end();
+
+  serverSide.resume();  // Dump the request
+  serverSide.end('HTTP/1.1 200 OK\r\n' +
+                 'Hello: foo\x08foo\r\n' +
+                 'Content-Length: 0\r\n' +
+                 '\r\n\r\n');
+}
+
+// Test 2: The same as Test 1 except without the option, to make sure it fails.
+{
+  const { clientSide, serverSide } = MakeDuplexPair();
+
+  const req = http.request({
+    createConnection: common.mustCall(() => clientSide)
+  }, common.mustNotCall());
+  req.end();
+  req.on('error', common.mustCall());
+
+  serverSide.resume();  // Dump the request
+  serverSide.end('HTTP/1.1 200 OK\r\n' +
+                 'Hello: foo\x08foo\r\n' +
+                 'Content-Length: 0\r\n' +
+                 '\r\n\r\n');
+}
+
+// Test 3: The client sends an invalid header.
+{
+  const testData = 'Hello, World!\n';
+  const server = http.createServer(
+    { insecureHTTPParser: true },
+    common.mustCall((req, res) => {
+      res.statusCode = 200;
+      res.setHeader('Content-Type', 'text/plain');
+      res.end(testData);
+    }));
+
+  server.on('clientError', common.mustNotCall());
+
+  const { clientSide, serverSide } = MakeDuplexPair();
+  serverSide.server = server;
+  server.emit('connection', serverSide);
+
+  clientSide.write('GET / HTTP/1.1\r\n' +
+                   'Hello: foo\x08foo\r\n' +
+                   '\r\n\r\n');
+}
+
+// Test 4: The same as Test 3 except without the option, to make sure it fails.
+{
+  const server = http.createServer(common.mustNotCall());
+
+  server.on('clientError', common.mustCall());
+
+  const { clientSide, serverSide } = MakeDuplexPair();
+  serverSide.server = server;
+  server.emit('connection', serverSide);
+
+  clientSide.write('GET / HTTP/1.1\r\n' +
+                   'Hello: foo\x08foo\r\n' +
+                   '\r\n\r\n');
+}