diff --git a/SurveyLib.Core/Services/IAnswerService.cs b/SurveyLib.Core/Services/IAnswerService.cs
index d2122dc..2eb866d 100644
--- a/SurveyLib.Core/Services/IAnswerService.cs
+++ b/SurveyLib.Core/Services/IAnswerService.cs
@@ -4,9 +4,9 @@ namespace SurveyLib.Core.Services;
 
 public interface IAnswerService
 {
-    Task<bool> AddAnswerAsync(Answer answer);
-    Task<bool> UpdateAnswerAsync(Answer answer);
-    Task<bool> DeleteAnswerAsync(int id);
+    Task AddAnswerAsync(Answer answer);
+    Task UpdateAnswerAsync(Answer answer);
+    Task DeleteAnswerAsync(int id);
     Task<IEnumerable<Answer>> GetAnswersByCompletionIdAsync(int completionId);
     Task<IEnumerable<Answer>> GetAnswersByQuestionIdAsync(int questionId);
 }
\ No newline at end of file
diff --git a/SurveyLib.Core/Services/ICompletionService.cs b/SurveyLib.Core/Services/ICompletionService.cs
index 3a9430d..b6d4bab 100644
--- a/SurveyLib.Core/Services/ICompletionService.cs
+++ b/SurveyLib.Core/Services/ICompletionService.cs
@@ -4,8 +4,8 @@ namespace SurveyLib.Core.Services;
 
 public interface ICompletionService
 {
-    Task<bool> AddCompletionAsync(Completion completion);
-    Task<bool> UpdateCompletionAsync(Completion completion);
-    Task<bool> DeleteCompletionAsync(int id);
+    Task AddCompletionAsync(Completion completion);
+    Task UpdateCompletionAsync(Completion completion);
+    Task DeleteCompletionAsync(int id);
     Task<IEnumerable<Completion>> GetCompletionsBySurveyIdAsync(int surveyId);
 }
\ No newline at end of file