diff --git a/Solver_interface/examples/Solver_interface/osqp_quadratic_program.cpp b/Solver_interface/examples/Solver_interface/osqp_quadratic_program.cpp
index a7f72d8b3ee..3bc9136db58 100644
--- a/Solver_interface/examples/Solver_interface/osqp_quadratic_program.cpp
+++ b/Solver_interface/examples/Solver_interface/osqp_quadratic_program.cpp
@@ -33,31 +33,28 @@ using FT = typename Kernel::FT;
 
 int main(void) {
 
-  CGAL::OSQP_quadratic_program_traits<FT> osqp;
+  const std::size_t n = 2; // number of variables
+  const std::size_t m = 3; // number of constraints
+  CGAL::OSQP_quadratic_program_traits<FT> osqp(n, m);
 
-  osqp.reserve_P(3);
   osqp.set_P(0, 0, 4);
   osqp.set_P(0, 1, 1);
   osqp.set_P(1, 1, 2);
 
-  osqp.reserve_q(2);
   osqp.set_q(0, 1);
   osqp.set_q(1, 1);
 
   osqp.set_r(0);
 
-  osqp.reserve_A(4);
   osqp.set_A(0, 0, 1);
   osqp.set_A(0, 1, 1);
   osqp.set_A(1, 0, 1);
   osqp.set_A(2, 1, 1);
 
-  osqp.reserve_l(3);
   osqp.set_l(0, 1);
   osqp.set_l(1, 0);
   osqp.set_l(2, 0);
 
-  osqp.reserve_u(3);
   osqp.set_u(0, 1);
   osqp.set_u(1, 0.7);
   osqp.set_u(2, 0.7);