diff --git a/Kyoo.Common/Utility.cs b/Kyoo.Common/Utility.cs
index 2922acec..19b23564 100644
--- a/Kyoo.Common/Utility.cs
+++ b/Kyoo.Common/Utility.cs
@@ -71,7 +71,7 @@ namespace Kyoo
 			if (isEqual == null)
 				return first.Concat(second).ToList();
 			List<T> list = first.ToList();
-			return list.Concat(second.Where(x => !list.Any(y => isEqual(x, y)))).ToList();
+			return list.Concat(second.Where(x => !list.Any(y => isEqual(x, y))));
 		}
 
 		public static T Assign<T>(T first, T second)
diff --git a/Kyoo/Controllers/Repositories/ShowRepository.cs b/Kyoo/Controllers/Repositories/ShowRepository.cs
index 03505365..0991eda7 100644
--- a/Kyoo/Controllers/Repositories/ShowRepository.cs
+++ b/Kyoo/Controllers/Repositories/ShowRepository.cs
@@ -84,9 +84,17 @@ namespace Kyoo.Controllers
 		{
 			await base.Create(obj);
 			_database.Entry(obj).State = EntityState.Added;
+			
 			if (obj.GenreLinks != null)
+			{
 				foreach (GenreLink entry in obj.GenreLinks)
+				{
+					if (!(entry.Genre is GenreDE))
+						entry.Genre = new GenreDE(entry.Genre);
 					_database.Entry(entry).State = EntityState.Added;
+				}
+			}
+
 			if (obj.People != null)
 				foreach (PeopleRole entry in obj.People)
 					_database.Entry(entry).State = EntityState.Added;
diff --git a/Kyoo/Models/Resources/CollectionDE.cs b/Kyoo/Models/Resources/CollectionDE.cs
index 3f23faf8..8cafc83f 100644
--- a/Kyoo/Models/Resources/CollectionDE.cs
+++ b/Kyoo/Models/Resources/CollectionDE.cs
@@ -7,21 +7,21 @@ namespace Kyoo.Models
 {
 	public class CollectionDE : Collection
 	{
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<CollectionLink> Links { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<CollectionLink> Links { get; set; }
 		[ExpressionRewrite(nameof(Links), nameof(CollectionLink.Show))]
 		public override IEnumerable<Show> Shows
 		{
 			get => Links?.Select(x => x.Show);
-			set => Links = value?.Select(x => new CollectionLink(this, x));
+			set => Links = value?.Select(x => new CollectionLink(this, x)).ToList();
 		}
 		
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<LibraryLink> LibraryLinks { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<LibraryLink> LibraryLinks { get; set; }
 		
 		[ExpressionRewrite(nameof(LibraryLinks), nameof(GenreLink.Genre))]
 		public override IEnumerable<Library> Libraries
 		{
 			get => LibraryLinks?.Select(x => x.Library);
-			set => LibraryLinks = value?.Select(x => new LibraryLink(x, this));
+			set => LibraryLinks = value?.Select(x => new LibraryLink(x, this)).ToList();
 		}
 		
 		public CollectionDE() {}
diff --git a/Kyoo/Models/Resources/GenreDE.cs b/Kyoo/Models/Resources/GenreDE.cs
index 3d5172ab..03443d66 100644
--- a/Kyoo/Models/Resources/GenreDE.cs
+++ b/Kyoo/Models/Resources/GenreDE.cs
@@ -7,13 +7,13 @@ namespace Kyoo.Models
 {
 	public class GenreDE : Genre
 	{
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<GenreLink> Links { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<GenreLink> Links { get; set; }
 
 		[ExpressionRewrite(nameof(Links), nameof(GenreLink.Genre))]
 		[JsonIgnore] [NotMergable] public override IEnumerable<Show> Shows
 		{
 			get => Links?.Select(x => x.Show);
-			set => Links = value?.Select(x => new GenreLink(x, this));
+			set => Links = value?.Select(x => new GenreLink(x, this)).ToList();
 		}
 
 		public GenreDE() {}
diff --git a/Kyoo/Models/Resources/LibraryDE.cs b/Kyoo/Models/Resources/LibraryDE.cs
index 652eaa88..3ddc6cd6 100644
--- a/Kyoo/Models/Resources/LibraryDE.cs
+++ b/Kyoo/Models/Resources/LibraryDE.cs
@@ -7,7 +7,7 @@ namespace Kyoo.Models
 {
 	public class LibraryDE : Library
 	{
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<ProviderLink> ProviderLinks { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<ProviderLink> ProviderLinks { get; set; }
 		[ExpressionRewrite(nameof(ProviderLinks), nameof(ProviderLink.Provider))]
 		public override IEnumerable<ProviderID> Providers
 		{
@@ -15,14 +15,14 @@ namespace Kyoo.Models
 			set => ProviderLinks = value?.Select(x => new ProviderLink(x, this)).ToList();
 		}
 		
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<LibraryLink> Links { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<LibraryLink> Links { get; set; }
 		[ExpressionRewrite(nameof(Links), nameof(LibraryLink.Show))]
 		public override IEnumerable<Show> Shows
 		{
 			get => Links?.Where(x => x.Show != null).Select(x => x.Show);
 			set => Links = Utility.MergeLists(
 				value?.Select(x => new LibraryLink(this, x)), 
-				Links?.Where(x => x.Show == null));
+				Links?.Where(x => x.Show == null))?.ToList();
 		}
 		[ExpressionRewrite(nameof(Links), nameof(LibraryLink.Collection))]
 		public override IEnumerable<Collection> Collections
@@ -30,7 +30,7 @@ namespace Kyoo.Models
 			get => Links?.Where(x => x.Collection != null).Select(x => x.Collection);
 			set => Links = Utility.MergeLists(
 				value?.Select(x => new LibraryLink(this, x)), 
-				Links?.Where(x => x.Collection == null));
+				Links?.Where(x => x.Collection == null))?.ToList();
 		}
 		
 		public LibraryDE() {}
diff --git a/Kyoo/Models/Resources/ShowDE.cs b/Kyoo/Models/Resources/ShowDE.cs
index c7c3b170..31d68100 100644
--- a/Kyoo/Models/Resources/ShowDE.cs
+++ b/Kyoo/Models/Resources/ShowDE.cs
@@ -10,28 +10,28 @@ namespace Kyoo.Models
 {
 	public class ShowDE : Show
 	{
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<GenreLink> GenreLinks { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<GenreLink> GenreLinks { get; set; }
 		[ExpressionRewrite(nameof(GenreLinks), nameof(GenreLink.Genre))]
 		public override IEnumerable<Genre> Genres
 		{
 			get => GenreLinks?.Select(x => x.Genre);
-			set => GenreLinks = value?.Select(x => new GenreLink(this, x));
+			set => GenreLinks = value?.Select(x => new GenreLink(this, x)).ToList();
 		}
 		
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<LibraryLink> LibraryLinks { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<LibraryLink> LibraryLinks { get; set; }
 		[ExpressionRewrite(nameof(LibraryLinks), nameof(LibraryLink.Library))]
 		public override IEnumerable<Library> Libraries
 		{
 			get => LibraryLinks?.Select(x => x.Library);
-			set => LibraryLinks = value?.Select(x => new LibraryLink(x, this));
+			set => LibraryLinks = value?.Select(x => new LibraryLink(x, this)).ToList();
 		}
 		
-		[JsonIgnore] [NotMergable] public virtual IEnumerable<CollectionLink> CollectionLinks { get; set; }
+		[JsonIgnore] [NotMergable] public virtual ICollection<CollectionLink> CollectionLinks { get; set; }
 		[ExpressionRewrite(nameof(CollectionLinks), nameof(CollectionLink.Collection))]
 		public override IEnumerable<Collection> Collections
 		{
 			get => CollectionLinks?.Select(x => x.Collection);
-			set => CollectionLinks = value?.Select(x => new CollectionLink(x, this));
+			set => CollectionLinks = value?.Select(x => new CollectionLink(x, this)).ToList();
 		}
 
 		public ShowDE() {}