diff --git a/include/sys/_types.h b/include/sys/_types.h
index e5ed18e..b8aeb97 100644
--- a/include/sys/_types.h
+++ b/include/sys/_types.h
@@ -47,6 +47,30 @@
 typedef long __suseconds_t; /* microseconds (signed) */
 typedef __int32_t	 __pid_t;/* process [group] */
 
+
+/*
+ * Unusual type definitions.
+ */
+/*
+ * rune_t is declared to be an ``int'' instead of the more natural
+ * ``unsigned long'' or ``long''.  Two things are happening here.  It is not
+ * unsigned so that EOF (-1) can be naturally assigned to it and used.  Also,
+ * it looks like 10646 will be a 31 bit standard.  This means that if your
+ * ints cannot hold 32 bits, you will be in trouble.  The reason an int was
+ * chosen over a long is that the is*() and to*() routines take ints (says
+ * ANSI C), but they use __ct_rune_t instead of int.
+ *
+ * NOTE: rune_t is not covered by ANSI nor other standards, and should not
+ * be instantiated outside of lib/libc/locale.  Use wchar_t.  wint_t and
+ * rune_t must be the same type.  Also, wint_t should be able to hold all
+ * members of the largest character set plus one extra value (WEOF), and
+ * must be at least 16 bits.
+ */
+typedef int             __ct_rune_t;    /* arg type for ctype funcs */
+typedef __ct_rune_t     __rune_t;       /* rune_t (see above) */
+typedef __ct_rune_t     __wint_t;       /* wint_t (see above) */
+
+
 #if !defined(__clang__) || !defined(__cplusplus)
 typedef __uint_least16_t   __char16_t;
 typedef __uint_least32_t   __char32_t;
diff --git a/sys/net/core/def.c b/sys/net/core/def.c
index 643b095..d1dbb9e 100644
--- a/sys/net/core/def.c
+++ b/sys/net/core/def.c
@@ -61,6 +61,7 @@
 #include "net/opt.h"
 #include "net/def.h"
 
+#include <stddef.h>
 #include <sys/types.h>
 #include <string.h>