diff --git a/listings/listing_8.1.cpp b/listings/listing_8.1.cpp
index f47f5a6..41647bc 100644
--- a/listings/listing_8.1.cpp
+++ b/listings/listing_8.1.cpp
@@ -11,7 +11,7 @@ struct sorter
         std::promise<std::list<T> > promise;
     };
 
-    thread_safe_stack<chunk_to_sort> chunks;
+    threadsafe_stack<chunk_to_sort> chunks;
     std::vector<std::thread> threads;
     unsigned const max_thread_count;
     std::atomic<bool> end_of_data;
@@ -32,7 +32,7 @@ struct sorter
 
     void try_sort_chunk()
     {
-        boost::shared_ptr<chunk_to_sort > chunk=chunks.pop();
+        std::shared_ptr<chunk_to_sort > chunk=chunks.pop();
         if(chunk)
         {
             sort_chunk(chunk);
@@ -79,7 +79,7 @@ struct sorter
         return result;
     }
 
-    void sort_chunk(boost::shared_ptr<chunk_to_sort > const& chunk)
+    void sort_chunk(std::shared_ptr<chunk_to_sort > const& chunk)
     {
         chunk->promise.set_value(do_sort(chunk->data));
     }