diff --git a/idlib/geometry/Winding2D.cpp b/idlib/geometry/Winding2D.cpp
index 3106d10..8978f1d 100644
--- a/idlib/geometry/Winding2D.cpp
+++ b/idlib/geometry/Winding2D.cpp
@@ -84,7 +84,7 @@ void idWinding2D::ExpandForAxialBox( const idVec2 bounds[2] ) {
 			continue;
 		}
 		plane = Plane2DFromPoints( p[i], p[j], true );
-		if ( i ) {
+		if ( numPlanes > 0 ) {
 			if ( GetAxialBevel( planes[numPlanes-1], plane, p[i], bevel ) ) {
 				planes[numPlanes++] = bevel;
 			}