diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index f03d674aee..2bd53f5e0a 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -191,6 +191,7 @@ namespace OpenRA.Traits
 		bool HasVoice(Actor self, string voice);
 	}
 
+	[RequireExplicitImplementation]
 	public interface IStoreResources { int Capacity { get; } }
 
 	public interface IEffectiveOwner