diff --git a/src/algorithm/BoundaryVisitor.cpp b/src/algorithm/BoundaryVisitor.cpp
index f6045a44..91c57e19 100644
--- a/src/algorithm/BoundaryVisitor.cpp
+++ b/src/algorithm/BoundaryVisitor.cpp
@@ -40,6 +40,8 @@ BoundaryVisitor::visit(const Point & /*g*/)
 void
 BoundaryVisitor::visit(const LineString &g)
 {
+  float z = 2;
+  double y = z;
   if (g.isEmpty()) {
     _boundary.reset();
     return;