diff --git a/IRaCIS.Core.Application/Service/Reading/ClinicalData/ClinicalAnswerService.cs b/IRaCIS.Core.Application/Service/Reading/ClinicalData/ClinicalAnswerService.cs
index 746b34b3c..ace7cc7da 100644
--- a/IRaCIS.Core.Application/Service/Reading/ClinicalData/ClinicalAnswerService.cs
+++ b/IRaCIS.Core.Application/Service/Reading/ClinicalData/ClinicalAnswerService.cs
@@ -527,7 +527,7 @@ namespace IRaCIS.Core.Application.Service
                 .WhereIf(inDto.ReadModuleId != null, x => x.Id == inDto.ReadModuleId)
                 .WhereIf(inDto.IsCRCConfirm != null, x => x.IsCRCConfirm == inDto.IsCRCConfirm)
                  .WhereIf(inDto.IsPMConfirm != null, x => x.IsPMConfirm == inDto.IsPMConfirm)
-                .WhereIf(inDto.SubjectCode != null, x => x.Subject.Code.Contains(inDto.SubjectCode))
+                .WhereIf(inDto.SubjectCode != null, x => x.Subject.Code.Contains(inDto.SubjectCode??string.Empty))
                 .WhereIf(inDto.TrialReadingCriterionId != null, x => x.TrialReadingCriterionId == inDto.TrialReadingCriterionId)
 				.WhereIf(inDto.SubjectId != null, x => x.SubjectId == inDto.SubjectId)
                 .WhereIf(inDto.StartTime != null, x => x.SubjectVisit.LatestScanDate >= inDto.StartTime)