diff --git a/kern/libkern/stddef.h b/kern/libkern/stddef.h
index 0d70dea..fa35dd3 100644
--- a/kern/libkern/stddef.h
+++ b/kern/libkern/stddef.h
@@ -1,8 +1,13 @@
 #ifndef STDDEF_H
 #define STDDEF_H
+#include <stdint.h>
 
 #ifndef NULL
 #define NULL ((void *)0)
 #endif
 
+#ifndef size_t
+#define size_t uint64_t
+#endif
+
 #endif // STDDEF_H