diff --git a/include/boost/numeric/ublas/storage_sparse.hpp b/include/boost/numeric/ublas/storage_sparse.hpp
index 154819df..2df2e98b 100644
--- a/include/boost/numeric/ublas/storage_sparse.hpp
+++ b/include/boost/numeric/ublas/storage_sparse.hpp
@@ -546,7 +546,7 @@ namespace boost { namespace numeric { namespace ublas {
         template<class I, class T, class ALLOC>
         BOOST_UBLAS_INLINE
         typename map_array<I, T, ALLOC>::size_type map_capacity (map_array<I, T, ALLOC> &m) {
-            m.capacity ();
+            return m.capacity ();
         }
     }