diff --git a/include/rfbclient.h b/include/rfbclient.h
index 37b3bb9..a8bfc2f 100644
--- a/include/rfbclient.h
+++ b/include/rfbclient.h
@@ -225,6 +225,9 @@ typedef char* (*GetUserProc)(struct _rfbClient* client);
 typedef char* (*GetSASLMechanismProc)(struct _rfbClient* client, char* mechlist);
 #endif /* LIBVNCSERVER_HAVE_SASL */
 
+typedef void (*NtpEventProc)(struct _rfbClient* client, uint32_t t0,
+                uint32_t t1, uint32_t t2, uint32_t t3);
+
 typedef struct _rfbClient {
 	uint8_t* frameBuffer;
 	int width, height;
@@ -467,6 +470,8 @@ typedef struct _rfbClient {
 
 	StartingFrameBufferUpdateProc StartingFrameBufferUpdate;
 	CancelledFrameBufferUpdateProc CancelledFrameBufferUpdate;
+
+	NtpEventProc NtpEvent;
 } rfbClient;
 
 /* cursor.c */
@@ -612,6 +617,9 @@ extern rfbBool HandleRFBServerMessage(rfbClient* client);
 
 extern rfbBool ReadToBuffer(rfbClient* client);
 
+extern rfbBool SendClientNtpEvent(rfbClient* client, uint32_t t0, uint32_t t1,
+		uint32_t t2, uint32_t t3);
+
 /**
  * Sends a text chat message to the server.
  * @param client The client through which to send the message
diff --git a/include/rfbproto.h b/include/rfbproto.h
index dbf3967..ffbceb4 100644
--- a/include/rfbproto.h
+++ b/include/rfbproto.h
@@ -398,8 +398,7 @@ typedef struct {
 #define rfbSetDesktopSize 251
 #define rfbQemuEvent 255
 
-
-
+#define rfbNtpEvent 160
 
 /*****************************************************************************
  *
@@ -499,6 +498,7 @@ typedef struct {
 #define rfbEncodingServerIdentity     0xFFFE0003
 
 #define rfbEncodingPts -1000
+#define rfbEncodingNtp -1001
 
 /*****************************************************************************
  *
@@ -1139,6 +1139,12 @@ typedef struct rfbExtDesktopScreen {
     uint32_t flags;
 } rfbExtDesktopScreen;
 
+struct rfbNtpMsg {
+	uint8_t type;
+	uint8_t padding[3];
+	uint32_t t0, t1, t2, t3;
+};
+
 #define sz_rfbExtDesktopSizeMsg (4)
 #define sz_rfbExtDesktopScreen (16)
 
@@ -1218,17 +1224,18 @@ typedef struct {
  */
 
 typedef union {
-    uint8_t type;
-    rfbFramebufferUpdateMsg fu;
-    rfbSetColourMapEntriesMsg scme;
-    rfbBellMsg b;
-    rfbServerCutTextMsg sct;
+	uint8_t type;
+	rfbFramebufferUpdateMsg fu;
+	rfbSetColourMapEntriesMsg scme;
+	rfbBellMsg b;
+	rfbServerCutTextMsg sct;
 	rfbResizeFrameBufferMsg rsfb;
 	rfbPalmVNCReSizeFrameBufferMsg prsfb; 
 	rfbFileTransferMsg ft;
 	rfbTextChatMsg tc;
 	rfbXvpMsg xvp;
 	rfbExtDesktopSizeMsg eds;
+	struct rfbNtpMsg ntp;
 } rfbServerToClientMsg;
 
 
diff --git a/include/vnc.h b/include/vnc.h
index bd36831..8c66811 100644
--- a/include/vnc.h
+++ b/include/vnc.h
@@ -45,6 +45,8 @@ struct vnc_client {
 	int (*alloc_fb)(struct vnc_client*);
 	void (*update_fb)(struct vnc_client*);
 	void (*cut_text)(struct vnc_client*, const char*, size_t);
+        void (*ntp_event)(struct vnc_client*, uint32_t t0, uint32_t t1,
+                        uint32_t t2, uint32_t t3);
 
 	void* userdata;
 	struct pixman_region16 damage;
@@ -79,3 +81,5 @@ void vnc_client_set_compression_level(struct vnc_client* self, int value);
 void vnc_client_send_cut_text(struct vnc_client* self, const char* text,
 		size_t len);
 void vnc_client_clear_av_frames(struct vnc_client* self);
+void vnc_client_send_ntp_event(struct vnc_client* self, uint32_t t0,
+                uint32_t t1, uint32_t t2, uint32_t t3);
diff --git a/src/rfbproto.c b/src/rfbproto.c
index 4ca8115..677d0be 100644
--- a/src/rfbproto.c
+++ b/src/rfbproto.c
@@ -1398,6 +1398,10 @@ rfbBool SetFormatAndEncodings(rfbClient* client)
 	if (se->nEncodings < MAX_ENCODINGS)
 		encs[se->nEncodings++] = rfbClientSwap32IfLE(rfbEncodingPts);
 
+	/* ntp */
+	if (se->nEncodings < MAX_ENCODINGS)
+		encs[se->nEncodings++] = rfbClientSwap32IfLE(rfbEncodingNtp);
+
 	len = sz_rfbSetEncodingsMsg + se->nEncodings * 4;
 
 	se->nEncodings = rfbClientSwap16IfLE(se->nEncodings);
@@ -1742,6 +1746,22 @@ rfbBool SendClientCutText(rfbClient* client, char* str, int len)
 	        WriteToRFBServer(client, str, len));
 }
 
+rfbBool SendClientNtpEvent(rfbClient* client, uint32_t t0, uint32_t t1,
+		uint32_t t2, uint32_t t3)
+{
+	if (!SupportsClient2Server(client, rfbNtpEvent))
+		return FALSE;
+
+	struct rfbNtpMsg msg = {
+		.type = rfbNtpEvent,
+		.t0 = rfbClientSwap32IfLE(t0),
+		.t1 = rfbClientSwap32IfLE(t1),
+		.t2 = rfbClientSwap32IfLE(t2),
+		.t3 = rfbClientSwap32IfLE(t3),
+	};
+	return WriteToRFBServer(client, (char*)&msg, sizeof(msg));
+}
+
 static rfbBool HandleFramebufferUpdate(rfbClient* client,
                                        rfbServerToClientMsg* msg)
 {
@@ -2300,6 +2320,10 @@ static rfbBool HandleFramebufferUpdate(rfbClient* client,
 			SetClient2Server(client, rfbQemuEvent);
 			break;
 
+		case rfbEncodingNtp:
+			SetClient2Server(client, rfbNtpEvent);
+			break;
+
 		default: {
 			rfbBool handled = FALSE;
 			rfbClientProtocolExtension* e;
@@ -2339,6 +2363,22 @@ failure:
 	return FALSE;
 }
 
+rfbBool handleNtpEvent(rfbClient* client, struct rfbNtpMsg* msg)
+{
+	if (!ReadFromRFBServer(client, (char*)msg + 1, sizeof(*msg) - 1))
+		return FALSE;
+
+	uint32_t t0 = rfbClientSwap32IfLE(msg->t0);
+	uint32_t t1 = rfbClientSwap32IfLE(msg->t1);
+	uint32_t t2 = rfbClientSwap32IfLE(msg->t2);
+	uint32_t t3 = rfbClientSwap32IfLE(msg->t3);
+
+	if (client->NtpEvent)
+		client->NtpEvent(client, t0, t1, t2, t3);
+
+	return TRUE;
+}
+
 /*
  * HandleRFBServerMessage.
  */
@@ -2527,6 +2567,9 @@ rfbBool HandleRFBServerMessage(rfbClient* client)
 		break;
 	}
 
+	case rfbNtpEvent:
+		return handleNtpEvent(client, &msg.ntp);
+
 	default: {
 		rfbBool handled = FALSE;
 		rfbClientProtocolExtension* e;
diff --git a/src/vnc.c b/src/vnc.c
index 100ec35..f7ebc8f 100644
--- a/src/vnc.c
+++ b/src/vnc.c
@@ -136,6 +136,16 @@ static void vnc_client_got_cut_text(rfbClient* client, const char* text,
 		self->cut_text(self, text, len);
 }
 
+static void vnc_client_ntp_event(rfbClient* client, uint32_t t0, uint32_t t1,
+		uint32_t t2, uint32_t t3)
+{
+	struct vnc_client* self = rfbClientGetClientData(client, NULL);
+	assert(self);
+
+	if (self->ntp_event)
+		self->ntp_event(self, t0, t1, t2, t3);
+}
+
 static rfbBool vnc_client_handle_open_h264_rect(rfbClient* client,
 		rfbFramebufferUpdateRectHeader* rect_header)
 {
@@ -246,6 +256,7 @@ struct vnc_client* vnc_client_create(void)
 	client->StartingFrameBufferUpdate = vnc_client_start_update;
 	client->CancelledFrameBufferUpdate = vnc_client_cancel_update;
 	client->GotXCutText = vnc_client_got_cut_text;
+	client->NtpEvent = vnc_client_ntp_event;
 
 	self->pts = NO_PTS;
 
@@ -443,3 +454,9 @@ void vnc_client_send_cut_text(struct vnc_client* self, const char* text,
 	// libvncclient doesn't modify text, so typecast is OK.
 	SendClientCutText(self->client, (char*)text, len);
 }
+
+void vnc_client_send_ntp_event(struct vnc_client* self, uint32_t t0,
+                uint32_t t1, uint32_t t2, uint32_t t3)
+{
+	SendClientNtpEvent(self->client, t0, t1, t2, t3);
+}