diff --git a/configure.ac b/configure.ac
index b19faea2..51c0bcde 100644
--- a/configure.ac
+++ b/configure.ac
@@ -300,6 +300,7 @@ AC_CHECK_HEADERS([argz.h \
                   malloc.h \
                   netdb.h \
                   netinet/in.h \
+                  netinet/tcp.h \
 		  poll.h \
 		  port.h \
                   stddef.h \
diff --git a/src/HttpServerCommand.cc b/src/HttpServerCommand.cc
index 18aae01c..75abb543 100644
--- a/src/HttpServerCommand.cc
+++ b/src/HttpServerCommand.cc
@@ -163,6 +163,7 @@ bool HttpServerCommand::execute()
         httpServer_->feedUpgradeResponse("websocket",
                                          fmt("Sec-WebSocket-Accept: %s\r\n",
                                              serverKey.c_str()));
+        httpServer_->getSocket()->setTcpNodelay(true);
         Command* command =
           new rpc::WebSocketResponseCommand(getCuid(), httpServer_, e_,
                                             socket_);
diff --git a/src/SocketCore.cc b/src/SocketCore.cc
index 7430e0a1..ec92571b 100644
--- a/src/SocketCore.cc
+++ b/src/SocketCore.cc
@@ -506,6 +506,12 @@ void SocketCore::joinMulticastGroup
   setSockOpt(IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
 }
 
+void SocketCore::setTcpNodelay(bool f)
+{
+  int val = f;
+  setSockOpt(IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val));
+}
+
 void SocketCore::setNonBlockingMode()
 {
 #ifdef __MINGW32__
diff --git a/src/SocketCore.h b/src/SocketCore.h
index eaf6d946..1627f4f1 100644
--- a/src/SocketCore.h
+++ b/src/SocketCore.h
@@ -125,6 +125,9 @@ public:
   (const std::string& multicastAddr, uint16_t multicastPort,
    const std::string& localAddr);
   
+  // Enables TCP_NODELAY socket option if f == true.
+  void setTcpNodelay(bool f);
+
   void create(int family, int protocol = 0);
 
   void bindWithFamily(uint16_t port, int family, int flags = AI_PASSIVE);
diff --git a/src/a2netcompat.h b/src/a2netcompat.h
index 5d4689fd..01be9c25 100644
--- a/src/a2netcompat.h
+++ b/src/a2netcompat.h
@@ -73,6 +73,10 @@
 # include <netinet/in.h>
 #endif // HAVE_NETINET_IN_H
 
+#ifdef HAVE_NETINET_TCP_H
+# include <netinet/tcp.h>
+#endif // HAVE_NETINET_TCP_H
+
 #ifdef HAVE_ARPA_INET_H
 # include <arpa/inet.h>
 #endif // HAVE_ARPA_INET_H