diff --git a/include/gp/containers/buffer.hpp b/include/gp/containers/buffer.hpp
index 3678429..5935a69 100644
--- a/include/gp/containers/buffer.hpp
+++ b/include/gp/containers/buffer.hpp
@@ -48,7 +48,7 @@ namespace gp{
 		, end_elem{beg_ptr+sz}
 		{}
 
-		constexpr typename pointer_iterator<T>::difference_type size() const
+		constexpr size_t size() const
 		{
 			return end_elem - begin_elem;
 		}