diff --git a/vio/viosslfactories.c b/vio/viosslfactories.c
index 35243d96a0b..5de052f18a3 100644
--- a/vio/viosslfactories.c
+++ b/vio/viosslfactories.c
@@ -134,6 +134,8 @@ static X509 *vio_gencert(EVP_PKEY *pkey)
     goto err;
   if (!(name= X509_get_subject_name(x)))
     goto err;
+  if (!ASN1_INTEGER_set(X509_get_serialNumber(x), 1))
+    goto err;
   if (!X509_NAME_add_entry_by_txt(name, "CN", MBSTRING_ASC,
          (uchar*)STRING_WITH_LEN("MariaDB Server"), -1, 0))
     goto err;