diff --git a/minitar.h b/minitar.h
index 0c96d0d..1d636ab 100644
--- a/minitar.h
+++ b/minitar.h
@@ -1,5 +1,6 @@
 #ifndef MINITAR_H
 #define MINITAR_H
+#include <stddef.h>
 #include <stdio.h>
 #include <sys/types.h>