diff --git a/include/continuable/detail/support/asio.hpp b/include/continuable/detail/support/asio.hpp
index 850ea5f..da885ef 100644
--- a/include/continuable/detail/support/asio.hpp
+++ b/include/continuable/detail/support/asio.hpp
@@ -35,15 +35,15 @@
 #include <asio/error_code.hpp>
 #include <asio/system_error.hpp>
 
-#define CTI_ASIO_NAMESPACE_BEGIN namespace asio {
-#define CTI_ASIO_NAMESPACE_END }
+#define CTI_DETAIL_ASIO_NAMESPACE_BEGIN namespace asio {
+#define CTI_DETAIL_ASIO_NAMESPACE_END }
 #else
 #include <boost/asio/async_result.hpp>
 #include <boost/system/error_code.hpp>
 #include <boost/system/system_error.hpp>
 
-#define CTI_ASIO_NAMESPACE_BEGIN namespace boost { namespace asio {
-#define CTI_ASIO_NAMESPACE_END }}
+#define CTI_DETAIL_ASIO_NAMESPACE_BEGIN namespace boost { namespace asio {
+#define CTI_DETAIL_ASIO_NAMESPACE_END }}
 #endif
 
 #include <utility>
diff --git a/include/continuable/support/asio.hpp b/include/continuable/support/asio.hpp
index a2a0c83..f1dfcbf 100644
--- a/include/continuable/support/asio.hpp
+++ b/include/continuable/support/asio.hpp
@@ -34,7 +34,7 @@
 #include <continuable/detail/support/asio.hpp>
 #include <continuable/detail/utility/traits.hpp>
 
-CTI_ASIO_NAMESPACE_BEGIN
+CTI_DETAIL_ASIO_NAMESPACE_BEGIN
 
 // Class used to specify an asynchronous operation should return a continuable.
 struct use_cti_t {};
@@ -65,6 +65,9 @@ public:
   }
 };
 
-CTI_ASIO_NAMESPACE_END
+CTI_DETAIL_ASIO_NAMESPACE_END
+
+#undef CTI_DETAIL_ASIO_NAMESPACE_BEGIN
+#undef CTI_DETAIL_ASIO_NAMESPACE_END
 
 #endif // CONTINUABLE_SUPPORT_ASIO_HPP_INCLUDED