diff --git a/Eigen/src/Core/SolveTriangular.h b/Eigen/src/Core/SolveTriangular.h
index b59cdbf85..7cbcf3d80 100644
--- a/Eigen/src/Core/SolveTriangular.h
+++ b/Eigen/src/Core/SolveTriangular.h
@@ -157,10 +157,10 @@ template<typename Lhs, typename Rhs, int Mode>
 struct triangular_solver_selector<Lhs,Rhs,OnTheRight,Mode,CompleteUnrolling,1> {
   static void run(const Lhs& lhs, Rhs& rhs)
   {
-    Transpose<Lhs> trLhs(lhs);
+    Transpose<const Lhs> trLhs(lhs);
     Transpose<Rhs> trRhs(rhs);
     
-    triangular_solver_unroller<Transpose<Lhs>,Transpose<Rhs>,
+    triangular_solver_unroller<Transpose<const Lhs>,Transpose<Rhs>,
                               ((Mode&Upper)==Upper ? Lower : Upper) | (Mode&UnitDiag),
                               0,Rhs::SizeAtCompileTime>::run(trLhs,trRhs);
   }