diff --git a/intern/bsp/intern/BSP_CSGMesh.cpp b/intern/bsp/intern/BSP_CSGMesh.cpp
index efc7ba0f706..a1da3d544ab 100755
--- a/intern/bsp/intern/BSP_CSGMesh.cpp
+++ b/intern/bsp/intern/BSP_CSGMesh.cpp
@@ -251,7 +251,7 @@ BuildEdges(
 	//edges
 	
 	vector<BSP_MFace>::const_iterator f_it_end = FaceSet().end();
-	vector<BSP_MFace>::const_iterator f_it_begin = FaceSet().begin();
+	vector<BSP_MFace>::iterator f_it_begin = FaceSet().begin();
 	vector<BSP_MFace>::iterator f_it = FaceSet().begin();
 
 	vector<BSP_MVertex> & vertex_set = VertexSet();