diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index 963095365d..2479ba4e5f 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -193,11 +193,6 @@ namespace OpenRA.Traits
 		bool HasFogVisibility();
 	}
 
-	public interface ITargetableCells
-	{
-		IEnumerable<Pair<CPos, SubCell>> TargetableCells();
-	}
-
 	public interface IOccupySpaceInfo : ITraitInfoInterface
 	{
 		IReadOnlyDictionary<CPos, SubCell> OccupiedCells(ActorInfo info, CPos location, SubCell subCell = SubCell.Any);
diff --git a/OpenRA.Mods.Common/Traits/Buildings/Building.cs b/OpenRA.Mods.Common/Traits/Buildings/Building.cs
index be7703aa48..59515fc0c9 100644
--- a/OpenRA.Mods.Common/Traits/Buildings/Building.cs
+++ b/OpenRA.Mods.Common/Traits/Buildings/Building.cs
@@ -287,7 +287,7 @@ namespace OpenRA.Mods.Common.Traits
 
 		public IEnumerable<Pair<CPos, SubCell>> OccupiedCells() { return occupiedCells; }
 
-		public IEnumerable<Pair<CPos, SubCell>> TargetableCells() { return targetableCells; }
+		IEnumerable<Pair<CPos, SubCell>> ITargetableCells.TargetableCells() { return targetableCells; }
 
 		void INotifyCreated.Created(Actor self)
 		{
diff --git a/OpenRA.Mods.Common/TraitsInterfaces.cs b/OpenRA.Mods.Common/TraitsInterfaces.cs
index 3507ee2849..83c1bd39f8 100644
--- a/OpenRA.Mods.Common/TraitsInterfaces.cs
+++ b/OpenRA.Mods.Common/TraitsInterfaces.cs
@@ -376,4 +376,10 @@ namespace OpenRA.Mods.Common.Traits
 		void OnAcceptingCash(Actor self, Actor donor);
 		void OnDeliveringCash(Actor self, Actor acceptor);
 	}
+
+	[RequireExplicitImplementation]
+	public interface ITargetableCells
+	{
+		IEnumerable<Pair<CPos, SubCell>> TargetableCells();
+	}
 }