diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index 1eee307eb2..967caafb8f 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -301,8 +301,11 @@ namespace OpenRA.Traits
 	[SuppressMessage("StyleCop.CSharp.NamingRules", "SA1302:InterfaceNamesMustBeginWithI", Justification = "Not a real interface, but more like a tag.")]
 	public interface UsesInit<T> : ITraitInfo where T : IActorInit { }
 
+	[RequireExplicitImplementation]
 	public interface INotifySelected { void Selected(Actor self); }
+	[RequireExplicitImplementation]
 	public interface INotifySelection { void SelectionChanged(); }
+
 	public interface IWorldLoaded { void WorldLoaded(World w, WorldRenderer wr); }
 	public interface ICreatePlayers { void CreatePlayers(World w); }
 
diff --git a/OpenRA.Mods.Common/Traits/ProductionQueueFromSelection.cs b/OpenRA.Mods.Common/Traits/ProductionQueueFromSelection.cs
index 61944c5ee8..e2ba0430b1 100644
--- a/OpenRA.Mods.Common/Traits/ProductionQueueFromSelection.cs
+++ b/OpenRA.Mods.Common/Traits/ProductionQueueFromSelection.cs
@@ -39,7 +39,7 @@ namespace OpenRA.Mods.Common.Traits
 			paletteWidget = Exts.Lazy(() => Ui.Root.GetOrNull(info.ProductionPaletteWidget) as ProductionPaletteWidget);
 		}
 
-		public void SelectionChanged()
+		void INotifySelection.SelectionChanged()
 		{
 			// Disable for spectators
 			if (world.LocalPlayer == null)