diff --git a/Doc/Tutorial/09-persistence/persistence.cc b/Doc/Tutorial/09-persistence/persistence.cc
index ffc7ac4a..5fd550b0 100644
--- a/Doc/Tutorial/09-persistence/persistence.cc
+++ b/Doc/Tutorial/09-persistence/persistence.cc
@@ -194,9 +194,8 @@ namespace OpenMesh {
         _v.clear();
 
         bytes += IO::restore( _is, N, _swap );
-
-        std::string key;
-        size_t      val;
+        value_type::key_type key;
+        value_type::mapped_type  val;
 
         for (size_t i=0; i<N && _is.good(); ++i)
         {