diff --git a/single_include/mio/mio.hpp b/single_include/mio/mio.hpp
index c568a46..2b79930 100644
--- a/single_include/mio/mio.hpp
+++ b/single_include/mio/mio.hpp
@@ -1758,3 +1758,5 @@ using shared_ummap_sink = basic_shared_mmap_sink<unsigned char>;
 } // namespace mio
 
 #endif // MIO_SHARED_MMAP_HEADER
+
+#undef max