diff --git a/isisd/isis_common.h b/isisd/isis_common.h
index 2633855..334d339 100644
--- a/isisd/isis_common.h
+++ b/isisd/isis_common.h
@@ -35,6 +35,7 @@
   u_char len;
 #define ISIS_PASSWD_TYPE_UNUSED   0
 #define ISIS_PASSWD_TYPE_CLEARTXT 1
+#define ISIS_PASSWD_TYPE_HMAC_MD5 54
 #define ISIS_PASSWD_TYPE_PRIVATE  255
   u_char type;
   /* Authenticate SNPs? */