diff --git a/lib/krb5/krb5.h b/lib/krb5/krb5.h
index 61730ec9b..2ee5ea3d7 100644
--- a/lib/krb5/krb5.h
+++ b/lib/krb5/krb5.h
@@ -236,7 +236,8 @@ typedef enum krb5_keytype {
     KEYTYPE_DES3	= 7,
     KEYTYPE_AES128	= 17,
     KEYTYPE_AES256	= 18,
-    KEYTYPE_ARCFOUR	= 23
+    KEYTYPE_ARCFOUR	= 23,
+    KEYTYPE_ARCFOUR_56	= 24
 } krb5_keytype;
 
 typedef EncryptionKey krb5_keyblock;