diff --git a/OpenRA.Game/Traits/TraitsInterfaces.cs b/OpenRA.Game/Traits/TraitsInterfaces.cs
index 673c1736c3..1eee307eb2 100644
--- a/OpenRA.Game/Traits/TraitsInterfaces.cs
+++ b/OpenRA.Game/Traits/TraitsInterfaces.cs
@@ -318,6 +318,7 @@ namespace OpenRA.Traits
 		IBotInfo Info { get; }
 	}
 
+	[RequireExplicitImplementation]
 	public interface IRenderOverlay { void Render(WorldRenderer wr); }
 
 	[RequireExplicitImplementation]
diff --git a/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs b/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
index 698470d82d..172e3ea1bc 100644
--- a/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/EditorResourceLayer.cs
@@ -169,7 +169,7 @@ namespace OpenRA.Mods.Common.Traits
 			return t;
 		}
 
-		public void Render(WorldRenderer wr)
+		void IRenderOverlay.Render(WorldRenderer wr)
 		{
 			if (wr.World.Type != WorldType.Editor)
 				return;
diff --git a/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs b/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs
index 3e7d156145..bd94557ffc 100644
--- a/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/ResourceLayer.cs
@@ -60,7 +60,7 @@ namespace OpenRA.Mods.Common.Traits
 			}
 		}
 
-		public void Render(WorldRenderer wr)
+		void IRenderOverlay.Render(WorldRenderer wr)
 		{
 			foreach (var kv in spriteLayers.Values)
 				kv.Draw(wr.Viewport);
diff --git a/OpenRA.Mods.Common/Traits/World/SmudgeLayer.cs b/OpenRA.Mods.Common/Traits/World/SmudgeLayer.cs
index 86d55f966f..e7a64a50c4 100644
--- a/OpenRA.Mods.Common/Traits/World/SmudgeLayer.cs
+++ b/OpenRA.Mods.Common/Traits/World/SmudgeLayer.cs
@@ -202,7 +202,7 @@ namespace OpenRA.Mods.Common.Traits
 				dirty.Remove(r);
 		}
 
-		public void Render(WorldRenderer wr)
+		void IRenderOverlay.Render(WorldRenderer wr)
 		{
 			render.Draw(wr.Viewport);
 		}
diff --git a/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs b/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
index 1cc2f7ccaa..a8e3388e45 100644
--- a/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
+++ b/OpenRA.Mods.D2k/Traits/World/BuildableTerrainLayer.cs
@@ -70,7 +70,7 @@ namespace OpenRA.Mods.D2k.Traits
 				dirty.Remove(r);
 		}
 
-		public void Render(WorldRenderer wr)
+		void IRenderOverlay.Render(WorldRenderer wr)
 		{
 			render.Draw(wr.Viewport);
 		}