diff --git a/ykcs11/objects.c b/ykcs11/objects.c
index 76cdd38..2b57e23 100644
--- a/ykcs11/objects.c
+++ b/ykcs11/objects.c
@@ -1335,6 +1335,8 @@ CK_RV check_create_cert(CK_ATTRIBUTE_PTR templ, CK_ULONG n,
     case CKA_SUBJECT:
     case CKA_ISSUER:
     case CKA_CERTIFICATE_TYPE:
+    case CKA_PRIVATE:
+    case CKA_SERIAL_NUMBER:
       // Ignore other attributes
       break;