diff --git a/include/boost/numeric/ublas/triangular.hpp b/include/boost/numeric/ublas/triangular.hpp
index 183e3361..c4c2a23c 100644
--- a/include/boost/numeric/ublas/triangular.hpp
+++ b/include/boost/numeric/ublas/triangular.hpp
@@ -2162,7 +2162,7 @@ namespace boost { namespace numeric { namespace ublas {
                 singular ().raise ();
 #endif
             value_type t = e2 () (n);
-            for (difference_type m = n + 1; m <(difference_type) e1 ().size2(); ++ m) {
+            for (difference_type m = n + 1; m < static_cast<difference_type>(e1 ().size2()); ++ m) {
               t -= e1 () (n, m)  * e2 () (m);
             }
             e2() (n) = t / e1 () (n, n);