diff --git a/include/boost/assert.hpp b/include/boost/assert.hpp
index 3a501dc..645404d 100644
--- a/include/boost/assert.hpp
+++ b/include/boost/assert.hpp
@@ -18,26 +18,26 @@
 
 //
 //  When BOOST_DEBUG is not defined, it defaults to 0 (off)
-//  for backward compatibility with programs that do not
-//  define a boost_error handler
+//  for compatibility with programs that do not expect asserts
+//  in the smart pointer class templates.
 //
-//  After a reasonable transition period, the default can be
-//  changed to something more appropriate.
+//  This default may be changed after an initial transition period.
 //
 
 #ifndef BOOST_DEBUG
 #define BOOST_DEBUG 0
 #endif
 
-bool boost_error(char const * expr, char const * func, char const * file, long line);
-
 #if BOOST_DEBUG
 
-#include <boost/current_function.hpp>
 #include <assert.h>
 
 #ifndef BOOST_ASSERT
 
+#include <boost/current_function.hpp>
+
+bool boost_error(char const * expr, char const * func, char const * file, long line);
+
 # define BOOST_ASSERT(expr) ((expr) || !boost_error(#expr, BOOST_CURRENT_FUNCTION, __FILE__, __LINE__) || (assert(expr), true))
 
 #endif // #ifndef BOOST_ASSERT
@@ -47,6 +47,6 @@ bool boost_error(char const * expr, char const * func, char const * file, long l
 #undef BOOST_ASSERT
 #define BOOST_ASSERT(expr) ((void)0)
 
-#endif // #ifdef BOOST_DEBUG
+#endif // #if BOOST_DEBUG
 
 #endif // #ifndef BOOST_ASSERT_HPP_INCLUDED