diff --git a/SqlData/Persistence/DependencyInjection.cs b/SqlData/Persistence/DependencyInjection.cs
index f98052c..2ebae49 100644
--- a/SqlData/Persistence/DependencyInjection.cs
+++ b/SqlData/Persistence/DependencyInjection.cs
@@ -22,16 +22,16 @@ public static class DependencyInjection
 
         services.AddDbContext<UberDbContext>(DbConfig);
 
-        services.AddScoped<ICampusDbContext>(provider => provider.GetService<CampusDbContext>()!);
-        services.AddScoped<IDisciplineDbContext>(provider => provider.GetService<DisciplineDbContext>()!);
-        services.AddScoped<IFacultyDbContext>(provider => provider.GetService<FacultyDbContext>()!);
-        services.AddScoped<IGroupDbContext>(provider => provider.GetService<GroupDbContext>()!);
-        services.AddScoped<ILectureHallDbContext>(provider => provider.GetService<LectureHallDbContext>()!);
-        services.AddScoped<ILessonAssociationDbContext>(provider => provider.GetService<LessonAssociationDbContext>()!);
-        services.AddScoped<IProfessorDbContext>(provider => provider.GetService<ProfessorDbContext>()!);
-        services.AddScoped<ILessonDbContext>(provider => provider.GetService<LessonDbContext>()!);
-        services.AddScoped<ITypeOfOccupationDbContext>(provider => provider.GetService<TypeOfOccupationDbContext>()!);
-        services.AddScoped<ISpecificWeekDbContext>(provider => provider.GetService<SpecificWeekDbContext>()!);
+        services.AddScoped<ICampusDbContext>(provider => provider.GetRequiredService<CampusDbContext>());
+        services.AddScoped<IDisciplineDbContext>(provider => provider.GetRequiredService<DisciplineDbContext>());
+        services.AddScoped<IFacultyDbContext>(provider => provider.GetRequiredService<FacultyDbContext>());
+        services.AddScoped<IGroupDbContext>(provider => provider.GetRequiredService<GroupDbContext>());
+        services.AddScoped<ILectureHallDbContext>(provider => provider.GetRequiredService<LectureHallDbContext>());
+        services.AddScoped<ILessonAssociationDbContext>(provider => provider.GetRequiredService<LessonAssociationDbContext>());
+        services.AddScoped<IProfessorDbContext>(provider => provider.GetRequiredService<ProfessorDbContext>());
+        services.AddScoped<ILessonDbContext>(provider => provider.GetRequiredService<LessonDbContext>());
+        services.AddScoped<ITypeOfOccupationDbContext>(provider => provider.GetRequiredService<TypeOfOccupationDbContext>());
+        services.AddScoped<ISpecificWeekDbContext>(provider => provider.GetRequiredService<SpecificWeekDbContext>());
 
         return services;