diff --git a/lib/_http_client.js b/lib/_http_client.js
index c3ef9de20498df..22ae85c92782ec 100644
--- a/lib/_http_client.js
+++ b/lib/_http_client.js
@@ -606,7 +606,6 @@ function tickOnSocket(req, socket) {
   req.connection = socket;
   parser.reinitialize(HTTPParser.RESPONSE);
   parser.socket = socket;
-  parser.incoming = null;
   parser.outgoing = req;
   req.parser = parser;
 
@@ -619,9 +618,6 @@ function tickOnSocket(req, socket) {
   // Propagate headers limit from request object to parser
   if (typeof req.maxHeadersCount === 'number') {
     parser.maxHeaderPairs = req.maxHeadersCount << 1;
-  } else {
-    // Set default value because parser may be reused from FreeList
-    parser.maxHeaderPairs = 2000;
   }
 
   parser.onIncoming = parserOnIncomingClient;
diff --git a/lib/_http_common.js b/lib/_http_common.js
index 7f53aca246b040..ab075dc817ed6f 100644
--- a/lib/_http_common.js
+++ b/lib/_http_common.js
@@ -41,6 +41,8 @@ const kOnBody = HTTPParser.kOnBody | 0;
 const kOnMessageComplete = HTTPParser.kOnMessageComplete | 0;
 const kOnExecute = HTTPParser.kOnExecute | 0;
 
+const MAX_HEADER_PAIRS = 2000;
+
 // Only called in the slow case where slow means
 // that the request headers were either fragmented
 // across multiple TCP packets or too large to be
@@ -65,12 +67,12 @@ function parserOnHeadersComplete(versionMajor, versionMinor, headers, method,
   const parser = this;
   const { socket } = parser;
 
-  if (!headers) {
+  if (headers === undefined) {
     headers = parser._headers;
     parser._headers = [];
   }
 
-  if (!url) {
+  if (url === undefined) {
     url = parser._url;
     parser._url = '';
   }
@@ -80,12 +82,12 @@ function parserOnHeadersComplete(versionMajor, versionMinor, headers, method,
                                  socket.server[kIncomingMessage]) ||
                                  IncomingMessage;
 
-  parser.incoming = new ParserIncomingMessage(socket);
-  parser.incoming.httpVersionMajor = versionMajor;
-  parser.incoming.httpVersionMinor = versionMinor;
-  parser.incoming.httpVersion = `${versionMajor}.${versionMinor}`;
-  parser.incoming.url = url;
-  parser.incoming.upgrade = upgrade;
+  const incoming = parser.incoming = new ParserIncomingMessage(socket);
+  incoming.httpVersionMajor = versionMajor;
+  incoming.httpVersionMinor = versionMinor;
+  incoming.httpVersion = `${versionMajor}.${versionMinor}`;
+  incoming.url = url;
+  incoming.upgrade = upgrade;
 
   var n = headers.length;
 
@@ -93,51 +95,48 @@ function parserOnHeadersComplete(versionMajor, versionMinor, headers, method,
   if (parser.maxHeaderPairs > 0)
     n = Math.min(n, parser.maxHeaderPairs);
 
-  parser.incoming._addHeaderLines(headers, n);
+  incoming._addHeaderLines(headers, n);
 
   if (typeof method === 'number') {
     // server only
-    parser.incoming.method = methods[method];
+    incoming.method = methods[method];
   } else {
     // client only
-    parser.incoming.statusCode = statusCode;
-    parser.incoming.statusMessage = statusMessage;
+    incoming.statusCode = statusCode;
+    incoming.statusMessage = statusMessage;
   }
 
-  return parser.onIncoming(parser.incoming, shouldKeepAlive);
+  return parser.onIncoming(incoming, shouldKeepAlive);
 }
 
 // XXX This is a mess.
 // TODO: http.Parser should be a Writable emits request/response events.
 function parserOnBody(b, start, len) {
-  var parser = this;
-  var stream = parser.incoming;
+  const stream = this.incoming;
 
   // if the stream has already been removed, then drop it.
-  if (!stream)
+  if (stream === null)
     return;
 
-  var socket = stream.socket;
-
   // pretend this was the result of a stream._read call.
   if (len > 0 && !stream._dumped) {
     var slice = b.slice(start, start + len);
     var ret = stream.push(slice);
     if (!ret)
-      readStop(socket);
+      readStop(this.socket);
   }
 }
 
 function parserOnMessageComplete() {
-  var parser = this;
-  var stream = parser.incoming;
+  const parser = this;
+  const stream = parser.incoming;
 
-  if (stream) {
+  if (stream !== null) {
     stream.complete = true;
     // Emit any trailing headers.
-    var headers = parser._headers;
-    if (headers) {
-      parser.incoming._addHeaderLines(headers, headers.length);
+    const headers = parser._headers;
+    if (headers.length) {
+      stream._addHeaderLines(headers, headers.length);
       parser._headers = [];
       parser._url = '';
     }
@@ -151,8 +150,8 @@ function parserOnMessageComplete() {
 }
 
 
-var parsers = new FreeList('parsers', 1000, function() {
-  var parser = new HTTPParser(HTTPParser.REQUEST);
+const parsers = new FreeList('parsers', 1000, function() {
+  const parser = new HTTPParser(HTTPParser.REQUEST);
 
   parser._headers = [];
   parser._url = '';
@@ -162,11 +161,9 @@ var parsers = new FreeList('parsers', 1000, function() {
   parser.incoming = null;
   parser.outgoing = null;
 
-  // Only called in the slow case where slow means
-  // that the request headers were either fragmented
-  // across multiple TCP packets or too large to be
-  // processed in a single run. This method is also
-  // called to process trailing HTTP headers.
+  parser.maxHeaderPairs = MAX_HEADER_PAIRS;
+
+  parser.onIncoming = null;
   parser[kOnHeaders] = parserOnHeaders;
   parser[kOnHeadersComplete] = parserOnHeadersComplete;
   parser[kOnBody] = parserOnBody;
@@ -188,12 +185,12 @@ function closeParserInstance(parser) { parser.close(); }
 function freeParser(parser, req, socket) {
   if (parser) {
     parser._headers = [];
+    parser._url = '';
+    parser.maxHeaderPairs = MAX_HEADER_PAIRS;
     parser.onIncoming = null;
     if (parser._consumed)
       parser.unconsume();
     parser._consumed = false;
-    if (parser.socket)
-      parser.socket.parser = null;
     parser.socket = null;
     parser.incoming = null;
     parser.outgoing = null;
diff --git a/lib/_http_server.js b/lib/_http_server.js
index a8389dbda62f0d..9087e6bb8a2168 100644
--- a/lib/_http_server.js
+++ b/lib/_http_server.js
@@ -342,14 +342,10 @@ function connectionListenerInternal(server, socket) {
   parser.reinitialize(HTTPParser.REQUEST);
   parser.socket = socket;
   socket.parser = parser;
-  parser.incoming = null;
 
   // Propagate headers limit from server instance to parser
   if (typeof server.maxHeadersCount === 'number') {
     parser.maxHeaderPairs = server.maxHeadersCount << 1;
-  } else {
-    // Set default value because parser may be reused from FreeList
-    parser.maxHeaderPairs = 2000;
   }
 
   var state = {
@@ -526,7 +522,7 @@ function onParserExecuteCommon(server, socket, parser, state, ret, d) {
     socket.removeListener('error', socketOnError);
     unconsume(parser, socket);
     parser.finish();
-    freeParser(parser, req, null);
+    freeParser(parser, req, socket);
     parser = null;
 
     var eventName = req.method === 'CONNECT' ? 'connect' : 'upgrade';