diff --git a/persistent-data/buffer.h b/persistent-data/buffer.h
index c0540c3..b1a7989 100644
--- a/persistent-data/buffer.h
+++ b/persistent-data/buffer.h
@@ -44,8 +44,7 @@ namespace persistent_data {
 	template <uint32_t Size = DEFAULT_BUFFER_SIZE, uint32_t Alignment = 512>
 	class buffer : private boost::noncopyable {
 	public:
-		BOOST_STATIC_ASSERT_MSG((Alignment > 1) & !(Alignment & (Alignment - 1)),
-					"Alignment must be a power of two.");
+		BOOST_STATIC_ASSERT((Alignment > 1) & !(Alignment & (Alignment - 1)));
 
 		static uint32_t const ALIGNMENT = Alignment;
 		typedef boost::shared_ptr<buffer> ptr;