diff --git a/src/lightmapper/doom_levelsubmesh.cpp b/src/lightmapper/doom_levelsubmesh.cpp
index 0406606..fba9199 100644
--- a/src/lightmapper/doom_levelsubmesh.cpp
+++ b/src/lightmapper/doom_levelsubmesh.cpp
@@ -701,6 +701,7 @@ void DoomLevelSubmesh::AddSurfaceToTile(DoomLevelMeshSurface& surf, std::map<Lig
 	if (surf.IsSky)
 	{
 		surf.LightmapTileIndex = -1;
+		return;
 	}
 
 	LightmapTileBinding binding;