diff --git a/kdc/digest.c b/kdc/digest.c
index e34039eaa..833ac5cc0 100644
--- a/kdc/digest.c
+++ b/kdc/digest.c
@@ -1331,10 +1331,24 @@ _kdc_do_digest(krb5_context context,
 		version, ireq.u.ntlmRequest.username);
 	break;
     }
-    default:
+    default: {
+	char *s;
+	krb5_set_error_string(context, "unknown operation to digest");
+	ret = EINVAL;
+
     failed:
+
+	s = krb5_get_error_message(context, ret);
+	if (s == NULL) {
+	    krb5_clear_error_string(context);
+	    goto out;
+	}
+	
+	kdc_log(context, config, 0, "Digest failed with: %s", s);
+
 	r.element = choice_DigestRepInner_error;
-	r.u.error.reason = strdup("unknown/failed operation");
+	r.u.error.reason = strdup("unknown error");
+	krb5_free_error_string(context, s);
 	if (r.u.error.reason == NULL) {
 	    krb5_set_error_string(context, "out of memory");
 	    ret = ENOMEM;
@@ -1343,6 +1357,7 @@ _kdc_do_digest(krb5_context context,
 	r.u.error.code = EINVAL;
 	break;
     }
+    }
 
     ASN1_MALLOC_ENCODE(DigestRepInner, buf.data, buf.length, &r, &size, ret);
     if (ret) {