diff --git a/src/myblockproblem.hh b/src/myblockproblem.hh
index ef25c3e04a73c67d0e3427b9653614384e1780e2..ceed350d18cafa30dbf5d86c060feda619b51eb8 100644
--- a/src/myblockproblem.hh
+++ b/src/myblockproblem.hh
@@ -105,7 +105,7 @@ class MyBlockProblem<ConvexProblemTypeTEMPLATE>::IterateObject {
       typename MatrixType::row_type::ConstIterator it;
       typename MatrixType::row_type::ConstIterator end = problem.A[i].end();
       for (it = problem.A[m].begin(); it != end; ++it) {
-        int j = it.index();
+        int const j = it.index();
         if (j == m)
           localA = &(*it); // localA = &A[m][m]