diff --git a/server/database/xorm.go b/server/database/xorm.go
index fb1dc17..217b6d1 100644
--- a/server/database/xorm.go
+++ b/server/database/xorm.go
@@ -64,7 +64,7 @@ func (x xDB) Put(domain string, cert *certificate.Resource) error {
 	}
 	defer sess.Close()
 
-	if exist, _ := sess.ID(c.Domain).Exist(); exist {
+	if exist, _ := sess.ID(c.Domain).Exist(new(Cert)); exist {
 		if _, err := sess.ID(c.Domain).Update(c); err != nil {
 			return err
 		}
diff --git a/server/database/xorm_test.go b/server/database/xorm_test.go
index 9c032ee..50d8a7f 100644
--- a/server/database/xorm_test.go
+++ b/server/database/xorm_test.go
@@ -37,7 +37,7 @@ func TestSanitizeWildcardCerts(t *testing.T) {
 	}))
 
 	// update existing cert
-	assert.Error(t, certDB.Put(".wildcard.de", &certificate.Resource{
+	assert.NoError(t, certDB.Put(".wildcard.de", &certificate.Resource{
 		Domain:      "*.wildcard.de",
 		Certificate: localhost_mock_directory_certificate,
 	}))