diff --git a/src/micro/uSynergy.c b/src/micro/uSynergy.c
index a8d01da4..dda97bc3 100644
--- a/src/micro/uSynergy.c
+++ b/src/micro/uSynergy.c
@@ -166,6 +166,21 @@ static void sSendMouseCallback(uSynergyContext *context)
 
 
 
+/**
+@brief Call mouse relative callback after a mouse event
+**/
+static void sSendMouseRelativeCallback(uSynergyContext *context, int16_t x, int16_t y)
+{
+	// Skip if no callback is installed
+	if (context->m_mouseRelativeCallback == 0L)
+		return;
+
+	// Send callback
+	context->m_mouseRelativeCallback(context->m_cookie, x, y);
+}
+
+
+
 /**
 @brief Send keyboard callback when a key has been pressed or released
 **/
@@ -319,6 +334,12 @@ static void sProcessMessage(uSynergyContext *context, const uint8_t *message)
 		context->m_mouseY = sNetToNative16(message+10);
 		sSendMouseCallback(context);
 	}
+	else if (USYNERGY_IS_PACKET("DMRM"))
+	{
+		// Mouse relative. Reply with CNOP
+		//		kMsgDMouseRelMove	= "DMRM%2i%2i"
+		sSendMouseRelativeCallback(context, sNetToNative16(message+8), sNetToNative16(message+10));
+	}
 	else if (USYNERGY_IS_PACKET("DMWM"))
 	{
 		// Mouse wheel
@@ -437,7 +458,6 @@ static void sProcessMessage(uSynergyContext *context, const uint8_t *message)
 		//		kMsgCScreenSaver 	= "CSEC%1i"
 		//		kMsgDKeyRepeat		= "DKRP%2i%2i%2i%2i"
 		//		kMsgDKeyRepeat1_0	= "DKRP%2i%2i%2i"
-		//		kMsgDMouseRelMove	= "DMRM%2i%2i"
 		//		kMsgEIncompatible	= "EICV%2i%2i"
 		//		kMsgEBusy 			= "EBSY"
 		//		kMsgEUnknown		= "EUNK"
@@ -514,6 +534,10 @@ static void sUpdateContext(uSynergyContext *context)
 	/* Eat packets */
 	for (;;)
 	{
+		/* If less than 4 bytes left in buffer, we can't even get the next packet length yet */
+		if(context->m_receiveOfs < 4)
+			return;
+
 		/* Grab packet length and bail out if the packet goes beyond the end of the buffer */
 		packlen = sNetToNative32(context->m_receiveBuffer);
 		if (packlen+4 > context->m_receiveOfs)
diff --git a/src/micro/uSynergy.h b/src/micro/uSynergy.h
index ef1efaa6..2de72bf6 100644
--- a/src/micro/uSynergy.h
+++ b/src/micro/uSynergy.h
@@ -255,6 +255,19 @@ typedef void		(*uSynergyMouseCallback)(uSynergyCookie cookie, uint16_t x, uint16
 
 
 
+/**
+@brief Mouse relative callback
+
+This callback is called when a mouse relative event happens.
+
+@param cookie		Cookie supplied in the Synergy context
+@param x			Mouse X motion
+@param y			Mouse Y motion
+**/
+typedef void		(*uSynergyMouseRelativeCallback)(uSynergyCookie cookie, int16_t x, int16_t y);
+
+
+
 /**
 @brief Key event callback
 
@@ -332,6 +345,7 @@ typedef struct
 	uSynergyTraceFunc				m_traceFunc;									/* Function for tracing status (can be NULL) */
 	uSynergyScreenActiveCallback	m_screenActiveCallback;							/* Callback for entering and leaving screen */
 	uSynergyMouseCallback			m_mouseCallback;								/* Callback for mouse events */
+	uSynergyMouseRelativeCallback	m_mouseRelativeCallback;						/* Callback for mouse relative events */
 	uSynergyKeyboardCallback		m_keyboardCallback;								/* Callback for keyboard events */
 	uSynergyJoystickCallback		m_joystickCallback;								/* Callback for joystick events */
 	uSynergyClipboardCallback		m_clipboardCallback;							/* Callback for clipboard events */