diff --git a/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp b/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
index bff87c5bd..cb6d2a42c 100644
--- a/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
+++ b/Minecraft.World/Network/Packets/SetEntityMotionPacket.cpp
@@ -73,18 +73,20 @@ void SetEntityMotionPacket::read(DataInputStream *dis) //throws IOException
 	}
 }
 
-void SetEntityMotionPacket::write(DataOutputStream *dos) //throws IOException 
+void SetEntityMotionPacket::write(DataOutputStream *dos) //throws IOException
 {
 	if( useBytes )
 	{
-		dos->writeShort(id | 0x800);
+		// Masking the id to 11 bits before writing to account for large entitty ids.
+		dos->writeShort((id & 0x07FF) | 0x800);
 		dos->writeByte(xa/16);
 		dos->writeByte(ya/16);
 		dos->writeByte(za/16);
 	}
 	else
 	{
-		dos->writeShort(id);
+		// same thing as line 80 here
+		dos->writeShort((id & 0x07FF));
 		dos->writeShort(xa);
 		dos->writeShort(ya);
 		dos->writeShort(za);