diff --git a/tools/quake3/q3map2/vis.c b/tools/quake3/q3map2/vis.c
index be1e8138..64107c71 100644
--- a/tools/quake3/q3map2/vis.c
+++ b/tools/quake3/q3map2/vis.c
@@ -65,7 +65,7 @@ fixedWinding_t *NewFixedWinding( int points ){
 		Error( "NewWinding: %i points", points );
 	}
 
-	size = sizeof( *w ) + sizeof( *w->points ) * points;
+	size = offsetof( fixedWinding_t, points ) + sizeof( *w->points ) * points;
 	w = safe_malloc( size );
 	memset( w, 0, size );
 
diff --git a/tools/quake3/q3map2/visflow.c b/tools/quake3/q3map2/visflow.c
index ff390b50..2664682c 100644
--- a/tools/quake3/q3map2/visflow.c
+++ b/tools/quake3/q3map2/visflow.c
@@ -1423,7 +1423,7 @@ void CreatePassages( int portalnum ){
 			/* ydnar: prefer correctness to stack overflow  */
 			//% memcpy( &in, p->winding, (int)((fixedWinding_t *)0)->points[p->winding->numpoints] );
 			if ( p->winding->numpoints <= MAX_POINTS_ON_FIXED_WINDING ) {
-				memcpy( &in, p->winding, sizeof( *p->winding ) + sizeof( *p->winding->points ) * p->winding->numpoints );
+				memcpy( &in, p->winding, offsetof( fixedWinding_t, points ) + sizeof( *p->winding->points ) * p->winding->numpoints );
 			}
 			else{
 				memcpy( &in, p->winding, sizeof( fixedWinding_t ) );