diff --git a/OpenRA.Game/Traits/World/ResourceLayer.cs b/OpenRA.Game/Traits/World/ResourceLayer.cs
index 041afe9198..dd8f9e4e28 100644
--- a/OpenRA.Game/Traits/World/ResourceLayer.cs
+++ b/OpenRA.Game/Traits/World/ResourceLayer.cs
@@ -64,6 +64,10 @@ namespace OpenRA.Traits
 			for (int x = map.XOffset; x < map.XOffset + map.Width; x++)
 				for (int y = map.YOffset; y < map.YOffset + map.Height; y++)
 				{
+					// Todo: Valid terrain should be specified in the resource
+					if (!w.IsCellBuildable(new int2(x,y), false))
+						continue;
+					
 					content[x, y].type = resourceTypes.FirstOrDefault(
 						r => r.info.ResourceType == w.Map.MapResources[x, y].type);
 					if (content[x, y].type != null)
diff --git a/OpenRA.Mods.RA/SeedsResource.cs b/OpenRA.Mods.RA/SeedsResource.cs
index d683693787..040a802787 100644
--- a/OpenRA.Mods.RA/SeedsResource.cs
+++ b/OpenRA.Mods.RA/SeedsResource.cs
@@ -48,6 +48,7 @@ namespace OpenRA.Mods.RA
 					.SkipWhile(p => resLayer.GetResource(p) == resourceType && resLayer.IsFull(p.X, p.Y))
 					.Cast<int2?>().FirstOrDefault();
 
+				// Todo: Valid terrain should be specified in the resource
 				if (cell != null &&
 					(resLayer.GetResource(cell.Value) == resourceType || resLayer.GetResource(cell.Value) == null) &&
 					self.World.IsCellBuildable(cell.Value, false))