diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h
index 32b9dcd..a0099e9 100644
--- a/include/linux/if_ether.h
+++ b/include/linux/if_ether.h
@@ -102,6 +102,7 @@
 #define ETH_P_HDLC	0x0019		/* HDLC frames			*/
 #define ETH_P_ARCNET	0x001A		/* 1A for ArcNet :-)            */
 #define ETH_P_DSA	0x001B		/* Distributed Switch Arch.	*/
+#define ETH_P_TRAILER	0x001C		/* Trailer switch tagging	*/
 #define ETH_P_PHONET	0x00F5		/* Nokia Phonet frames          */
 
 /*