diff --git a/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php b/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
index e4e1f82fc..7c9006a7e 100644
--- a/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
@@ -30,6 +30,7 @@ class ContainerSetContentPacket extends DataPacket{
 	const NETWORK_ID = ProtocolInfo::CONTAINER_SET_CONTENT_PACKET;
 
 	const SPECIAL_INVENTORY = 0;
+	const SPECIAL_OFFHAND = 0x77;
 	const SPECIAL_ARMOR = 0x78;
 	const SPECIAL_CREATIVE = 0x79;
 	const SPECIAL_HOTBAR = 0x7a;