diff --git a/base_from_member_test.cpp b/base_from_member_test.cpp
index c422913..82f0d43 100644
--- a/base_from_member_test.cpp
+++ b/base_from_member_test.cpp
@@ -57,7 +57,7 @@ struct object_id_compare
 // A singleton of this type coordinates the acknowledgements
 // of objects being created and used.
 class object_registrar
-    : boost::noncopyable
+    : private boost::noncopyable
 {
 public:
 
diff --git a/noncopyable_test.cpp b/noncopyable_test.cpp
index 6ff951d..9986401 100644
--- a/noncopyable_test.cpp
+++ b/noncopyable_test.cpp
@@ -20,7 +20,7 @@
 
 namespace
 {
-    class DontTreadOnMe : boost::noncopyable
+    class DontTreadOnMe : private boost::noncopyable
     {
     public:
          DontTreadOnMe() { std::cout << "defanged!" << std::endl; }