diff --git a/include/boost/numeric/ublas/fwd.hpp b/include/boost/numeric/ublas/fwd.hpp
index 2991bb54..6678bf9b 100644
--- a/include/boost/numeric/ublas/fwd.hpp
+++ b/include/boost/numeric/ublas/fwd.hpp
@@ -102,6 +102,9 @@ namespace boost { namespace numeric { namespace ublas {
     template<class T>
     class unit_vector;
 
+    template<class T>
+    class zero_vector;
+
     template<class T>
     class scalar_vector;
 
@@ -133,6 +136,9 @@ namespace boost { namespace numeric { namespace ublas {
     template<class T>
     class identity_matrix;
 
+    template<class T>
+    class zero_matrix;
+
     template<class T>
     class scalar_matrix;