diff --git a/src/gl/data/gl_setup.cpp b/src/gl/data/gl_setup.cpp
index 26aee78b76..35c33199ae 100644
--- a/src/gl/data/gl_setup.cpp
+++ b/src/gl/data/gl_setup.cpp
@@ -420,7 +420,7 @@ static void InitVertexData()
 
 	for(unsigned i = 0; i < level.vertexes.Size(); ++i)
 	{
-		auto vert = level.vertexes[i];
+		auto &vert = level.vertexes[i];
 		int cnt = vt_sectorlists[i].Size();
 
 		vert.dirty = true;