diff --git a/authenticator/ldap_test.go b/authenticator/ldap_test.go
index 407a33b..e31639a 100644
--- a/authenticator/ldap_test.go
+++ b/authenticator/ldap_test.go
@@ -352,6 +352,8 @@ func TestGetCNFromDN(t *testing.T) {
 	res = getCNFromDN("cn=test")
 	assert.Equal(t, "test", res)
 	res = getCNFromDN("test")
+	assert.Equal(t, "test", res)
+	res = getCNFromDN("")
 	assert.Empty(t, res)
 	res = getCNFromDN("cn=admin ,ou=users,dc=mylab,dc=local")
 	assert.Equal(t, "admin", res)
diff --git a/authenticator/utils.go b/authenticator/utils.go
index 15f61ef..4ec9c47 100644
--- a/authenticator/utils.go
+++ b/authenticator/utils.go
@@ -85,6 +85,7 @@ func getCNFromDN(dn string) string {
 		if strings.HasPrefix(cn, "cn=") || strings.HasPrefix(cn, "ou=") {
 			return strings.TrimSpace(cn[3:])
 		}
+		return cn
 	}
 	return ""
 }