diff --git a/IRaCIS.Core.Application/Service/Doctor/DoctorService.cs b/IRaCIS.Core.Application/Service/Doctor/DoctorService.cs
index 8c452b890..4f4a09421 100644
--- a/IRaCIS.Core.Application/Service/Doctor/DoctorService.cs
+++ b/IRaCIS.Core.Application/Service/Doctor/DoctorService.cs
@@ -79,7 +79,7 @@ namespace IRaCIS.Application.Services
                     return ResponseOutput.NotOk(_localizer["Doctor_DupEmail"], new DoctorBasicInfoCommand());
                 }
 
-                doctor.Code = (await _doctorRepository.MaxAsync(t => t.Code)) + 1;
+                doctor.Code = await _doctorRepository.Select(t => t.Code).DefaultIfEmpty().MaxAsync() + 1;
 
                 doctor.ReviewerCode = AppSettings.GetCodeStr(doctor.Code, nameof(Doctor));
 
diff --git a/IRaCIS.Core.Application/Service/Institution/SiteService.cs b/IRaCIS.Core.Application/Service/Institution/SiteService.cs
index 4a78b453a..9d77f48ed 100644
--- a/IRaCIS.Core.Application/Service/Institution/SiteService.cs
+++ b/IRaCIS.Core.Application/Service/Institution/SiteService.cs
@@ -67,7 +67,7 @@ namespace IRaCIS.Application.Services
 
                     siteCommand.Code = await _siteRepository.Select(t => t.Code).DefaultIfEmpty().MaxAsync() + 1;
 
-                    siteCommand.SiteCode = AppSettings.GetCodeStr(siteCommand.Code, nameof(User));
+                    siteCommand.SiteCode = AppSettings.GetCodeStr(siteCommand.Code, nameof(Site));
                 }
 
                 var site = await _siteRepository.InsertOrUpdateAsync(siteCommand, true, exp);