diff --git a/DigitalData.Core.Infrastructure/DbRepository.cs b/DigitalData.Core.Infrastructure/DbRepository.cs
index 419ffc8..0fece54 100644
--- a/DigitalData.Core.Infrastructure/DbRepository.cs
+++ b/DigitalData.Core.Infrastructure/DbRepository.cs
@@ -12,9 +12,9 @@ public class DbRepository<TDbContext, TEntity> : IRepository<TEntity> where TDbC
 
     protected internal readonly DbSet<TEntity> Entities;
 
-    public IMapper Mapper { get; }
+    public IMapper? Mapper { get; }
 
-    public DbRepository(TDbContext context, DbSetFactory<TDbContext, TEntity> factory, IMapper mapper)
+    public DbRepository(TDbContext context, DbSetFactory<TDbContext, TEntity> factory, IMapper? mapper = null)
     {
         Context = context;
         Entities = factory.Create(context);
@@ -35,10 +35,10 @@ public class DbRepository<TDbContext, TEntity> : IRepository<TEntity> where TDbC
         return entities;
     }
 
-    public Task<TEntity> CreateAsync<TDto>(TDto dto, CancellationToken cancel = default) => CreateAsync(Mapper.Map<TEntity>(dto), cancel);
+    public Task<TEntity> CreateAsync<TDto>(TDto dto, CancellationToken cancel = default) => CreateAsync(Mapper!.Map<TEntity>(dto), cancel);
 
     public Task<IEnumerable<TEntity>> CreateAsync<TDto>(IEnumerable<TDto> dtos, CancellationToken cancel = default) 
-        => CreateAsync(Mapper.Map<IEnumerable<TEntity>>(dtos), cancel);
+        => CreateAsync(Mapper!.Map<IEnumerable<TEntity>>(dtos), cancel);
 
     public IQueryable<TEntity> Where(Expression<Func<TEntity, bool>> expression) => Entities.AsNoTracking().Where(expression);
 
@@ -54,7 +54,7 @@ public class DbRepository<TDbContext, TEntity> : IRepository<TEntity> where TDbC
 
         for (int i = entities.Count - 1; i >= 0; i--)
         {
-            Mapper.Map(dto, entities[i]);
+            Mapper!.Map(dto, entities[i]);
             Entities.Update(entities[i]);
         }