diff --git a/sfml-const/fix2.cpp b/sfml-const/fix2.cpp
index 34a4ddd..83984fc 100644
--- a/sfml-const/fix2.cpp
+++ b/sfml-const/fix2.cpp
@@ -1,5 +1,6 @@
 #include <iostream>
 #include "fix2.hpp"
+#include <cassert>
 
 using std::cout;
 
@@ -8,19 +9,21 @@ void RenderTarget::draw(const Drawable& drawable) {
 }
 
 void Shape::draw(RenderTarget& target) const {
-  cout << "shape draw\n";
+  assert(false && "You should not call this, use shape.draw(target) instead.");
 }
 
 void Shape::draw(RenderTarget &target) {
-  cout << "shape non-const instead\n";
+  cout << "shape renders without const instead\n";
 }
 
 int main() {
   RenderTarget target;
   Shape shape;
 
-  target.draw(shape);
+  // uncomment this to see the error when used wrong
+  // target.draw(shape);
 
   shape.draw(target);
+
   return 0;
 }