diff --git a/src/net/quic/quic_proxy_client_socket.cc b/src/net/quic/quic_proxy_client_socket.cc
index 7ebbcf64e8..9f9c5c634f 100644
--- a/src/net/quic/quic_proxy_client_socket.cc
+++ b/src/net/quic/quic_proxy_client_socket.cc
@@ -46,6 +46,8 @@ QuicProxyClientSocket::QuicProxyClientSocket(
       proxy_chain_index_(proxy_chain_index),
       proxy_delegate_(proxy_delegate),
       user_agent_(user_agent),
+      use_fastopen_(false),
+      read_headers_pending_(false),
       net_log_(net_log) {
   DCHECK(stream_->IsOpen());
 
@@ -326,6 +328,16 @@ int QuicProxyClientSocket::DoLoop(int last_io_result) {
       case STATE_PROCESS_RESPONSE_CODE:
         DCHECK_EQ(OK, rv);
         rv = DoProcessResponseCode();
+        if (use_fastopen_ && read_headers_pending_) {
+          read_headers_pending_ = false;
+          if (rv < 0) {
+            // read_callback_ will be called with this error and be reset.
+            // Further data after that will be ignored.
+            next_state_ = STATE_DISCONNECTED;
+          }
+          // Prevents calling connect_callback_.
+          rv = ERR_IO_PENDING;
+        }
         break;
       default:
         NOTREACHED() << "bad state";
@@ -387,6 +399,11 @@ int QuicProxyClientSocket::DoCalculateHeadersComplete(int result) {
     return result;
   }
   next_state_ = STATE_SEND_REQUEST;
+  if (proxy_delegate_headers_.HasHeader("fastopen")) {
+    proxy_delegate_headers_.RemoveHeader("fastopen");
+    // TODO(klzgrad): look into why Fast Open does not work.
+    use_fastopen_ = true;
+  }
   request_.extra_headers.MergeFrom(proxy_delegate_headers_);
   return result;
 }
@@ -431,6 +448,11 @@ int QuicProxyClientSocket::DoReadReply() {
       &response_header_block_,
       base::BindOnce(&QuicProxyClientSocket::OnReadResponseHeadersComplete,
                      weak_factory_.GetWeakPtr()));
+  if (use_fastopen_ && rv == ERR_IO_PENDING) {
+    read_headers_pending_ = true;
+    next_state_ = STATE_CONNECT_COMPLETE;
+    return OK;
+  }
   if (rv == ERR_IO_PENDING)
     return ERR_IO_PENDING;
   if (rv < 0)
@@ -499,6 +521,13 @@ int QuicProxyClientSocket::DoProcessResponseCode() {
 
 void QuicProxyClientSocket::OnReadResponseHeadersComplete(int result) {
   // Convert the now-populated quiche::HttpHeaderBlock to HttpResponseInfo
+  if (use_fastopen_ && read_headers_pending_) {
+    if (next_state_ == STATE_DISCONNECTED)
+      return;
+    if (next_state_ == STATE_CONNECT_COMPLETE)
+      next_state_ = STATE_READ_REPLY_COMPLETE;
+  }
+
   if (result > 0)
     result = ProcessResponseHeaders(response_header_block_);
 
diff --git a/src/net/quic/quic_proxy_client_socket.h b/src/net/quic/quic_proxy_client_socket.h
index eb74348630..df9cde7aab 100644
--- a/src/net/quic/quic_proxy_client_socket.h
+++ b/src/net/quic/quic_proxy_client_socket.h
@@ -164,6 +164,12 @@ class NET_EXPORT_PRIVATE QuicProxyClientSocket : public ProxyClientSocket {
 
   std::string user_agent_;
 
+  // Session connect timing info.
+  LoadTimingInfo::ConnectTiming connect_timing_;
+
+  bool use_fastopen_;
+  bool read_headers_pending_;
+
   const NetLogWithSource net_log_;
 
   // The default weak pointer factory.