diff --git a/tools/font_converter.py b/tools/font_converter.py
index 3997660..c73f196 100644
--- a/tools/font_converter.py
+++ b/tools/font_converter.py
@@ -36,6 +36,8 @@ for id, x, y, width, height, xoffset, yoffset, xadvance in re.findall(r"id=(\d+)
 string: str = f"""\
 #pragma once
 
+#include <stddef.h>
+
 #include "font.h"
 
 struct font {font_name}_font[] = {{\\\