diff --git a/kern/libkern/stddef.h b/kern/libkern/stddef.h
new file mode 100644
index 0000000..ab8a2b5
--- /dev/null
+++ b/kern/libkern/stddef.h
@@ -0,0 +1,9 @@
+#ifndef STDDEF_H
+#define STDDEF_H
+
+#ifndef NULL
+#define NULL ((void*)0)
+#endif
+
+#endif // STDDEF_H
+