diff --git a/include/crc32/crc32.hpp b/include/crc32/crc32.hpp
index e762563..84b76b9 100644
--- a/include/crc32/crc32.hpp
+++ b/include/crc32/crc32.hpp
@@ -10,13 +10,13 @@
 
 // uint8_t, uint32_t, int32_t
 extern "C" {
+#include <cstddef>  // size_t
+
 #include <stdint.h>
 
 #include "crc32/crc32.h"
 #include "crc32/crc32_var.h"
 
-#include <cstddef> // size_t
-
 #if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || __cplusplus >= 201703L)
 #  include <string_view>
 #else