diff --git a/src/myconvexproblem.hh b/src/myconvexproblem.hh
index ee91633d23f12294378d995ad61a79edc77ed709..ecbd73ce9d58618fc6f81008ab805c513ef6b6b3 100644
--- a/src/myconvexproblem.hh
+++ b/src/myconvexproblem.hh
@@ -31,16 +31,16 @@ class MyConvexProblem {
       \param f The linear functional
       \param u The solution vector
   */
-  MyConvexProblem(const MatrixType& A, NonlinearityType& phi,
-                  const VectorType& f, VectorType& u)
+  MyConvexProblem(MatrixType const &A, NonlinearityType &phi,
+                  VectorType const &f, VectorType &u)
       : A(A), phi(phi), f(f), u(u) {};
 
-  const MatrixType& A;
-  NonlinearityType& phi;
+  MatrixType const &A;
+  NonlinearityType φ
 
-  const VectorType& f;
+  VectorType const &f;
 
-  VectorType& u;
+  VectorType &u;
 };
 
 #endif