diff --git a/include/boost/circular_buffer/space_optimized.hpp b/include/boost/circular_buffer/space_optimized.hpp
index 21681fd3..7c7a17bb 100644
--- a/include/boost/circular_buffer/space_optimized.hpp
+++ b/include/boost/circular_buffer/space_optimized.hpp
@@ -8,6 +8,12 @@
 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
+// Include the main header before this file's guard so it can include this file
+// while the internal configuration macros are still defined.
+#if !defined(BOOST_CIRCULAR_BUFFER_HPP)
+#include <boost/circular_buffer.hpp>
+#endif
+
 #if !defined(BOOST_CIRCULAR_BUFFER_SPACE_OPTIMIZED_HPP)
 #define BOOST_CIRCULAR_BUFFER_SPACE_OPTIMIZED_HPP
 
diff --git a/test/space_optimized_test.cpp b/test/space_optimized_test.cpp
index 8694fcdb..0bf3751b 100644
--- a/test/space_optimized_test.cpp
+++ b/test/space_optimized_test.cpp
@@ -6,6 +6,9 @@
 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
 
+// Include the adaptor header first to check that it is self-contained.
+#define BOOST_CB_TEST
+#include <boost/circular_buffer/space_optimized.hpp>
 #include "test.hpp"
 
 #define CB_CONTAINER circular_buffer_space_optimized