diff --git a/lib/krb5/transited.c b/lib/krb5/transited.c
index a9b34dfc6..8cac643b5 100644
--- a/lib/krb5/transited.c
+++ b/lib/krb5/transited.c
@@ -368,6 +368,11 @@ krb5_domain_x500_encode(char **realms, int num_realms, krb5_data *encoding)
     char *s = NULL;
     int len = 0;
     int i;
+    if (num_realms == 0) {
+	encoding->data = NULL;
+	encoding->length = 0;
+	return 0;
+    }
     for(i = 0; i < num_realms; i++){
 	len += strlen(realms[i]);
 	if(realms[i][0] == '/')
@@ -375,6 +380,8 @@ krb5_domain_x500_encode(char **realms, int num_realms, krb5_data *encoding)
     }
     len += num_realms - 1;
     s = malloc(len + 1);
+    if (s == NULL)
+	return ENOMEM;
     *s = '\0';
     for(i = 0; i < num_realms; i++){
 	if(i && i < num_realms - 1)