diff --git a/lib/krb5/generate_seq_number.c b/lib/krb5/generate_seq_number.c
index 24d1db0c6..fe160e72b 100644
--- a/lib/krb5/generate_seq_number.c
+++ b/lib/krb5/generate_seq_number.c
@@ -45,19 +45,23 @@ krb5_generate_seq_number(krb5_context context,
 			 const krb5_keyblock *key,
 			 int32_t *seqno)
 {
-    des_cblock c;
-    int32_t q;
+    krb5_error_code ret;
+    krb5_keyblock *subkey;
+    u_int32_t q;
     u_char *p;
     int i;
 
-    if (key->keytype != KEYTYPE_DES)
-	abort ();
-    memmove (c, key->keyvalue.data, sizeof(c));
-    des_new_random_key(&c);
+    ret = krb5_generate_subkey (context, key, &subkey);
+    if (ret)
+	return ret;
+
     q = 0;
-    for (p = (u_char *)c, i = 0; i < sizeof(c); ++i, ++p)
+    for (p = (u_char *)subkey->keyvalue.data, i = 0;
+	 i < subkey->keyvalue.length;
+	 ++i, ++p)
 	q = (q << 8) | *p;
     q &= 0xffffffff;
     *seqno = q;
+    krb5_free_keyblock (context, subkey);
     return 0;
 }