diff --git a/framework/src/Volo.Abp.Ldap/Volo/Abp/Ldap/AbpLdapModule.cs b/framework/src/Volo.Abp.Ldap/Volo/Abp/Ldap/AbpLdapModule.cs
index 3978a1b1c1..189af6eb41 100644
--- a/framework/src/Volo.Abp.Ldap/Volo/Abp/Ldap/AbpLdapModule.cs
+++ b/framework/src/Volo.Abp.Ldap/Volo/Abp/Ldap/AbpLdapModule.cs
@@ -1,4 +1,5 @@
-using Microsoft.Extensions.DependencyInjection;
+using System;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.DependencyInjection.Extensions;
 using Microsoft.Extensions.Options;
 using Volo.Abp.Ldap.Localization;