Index: sys/sys/mbuf.h
===================================================================
--- sys/sys/mbuf.h
+++ sys/sys/mbuf.h
@@ -38,7 +38,7 @@
 
 /* XXX: These includes suck. Sorry! */
 #include <sys/queue.h>
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_KERNEL_UT)
 #include <sys/systm.h>
 #include <sys/refcount.h>
 #include <vm/uma.h>
@@ -47,7 +47,7 @@
 #endif
 #endif
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_KERNEL_UT)
 #include <sys/sdt.h>
 
 #define	MBUF_PROBE1(probe, arg0)					\
@@ -74,7 +74,7 @@
 SDT_PROBE_DECLARE(sdt, , , m__free);
 SDT_PROBE_DECLARE(sdt, , , m__freem);
 
-#endif /* _KERNEL */
+#endif /* _KERNEL || _KERNEL_UT */
 
 /*
  * Mbufs are of a single size, MSIZE (sys/param.h), which includes overhead.
@@ -104,7 +104,7 @@
 #define	MINCLSIZE	(MHLEN + 1)
 #define	M_NODOM		255
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_KERNEL_UT)
 /*-
  * Macro for type conversion: convert mbuf pointer to data pointer of correct
  * type:
@@ -123,7 +123,7 @@
 	int	flags;	/* Flags for mbuf being allocated */
 	short	type;	/* Type of mbuf being allocated */
 };
-#endif /* _KERNEL */
+#endif /* _KERNEL || _KERNEL_UT */
 
 /*
  * Packet tag structure (see below for details).
@@ -400,7 +400,7 @@
 	};
 };
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_KERNEL_UT)
 static inline int
 m_epg_pagelen(const struct mbuf *m, int pidx, int pgoff)
 {
@@ -771,7 +771,7 @@
 #define	MBUF_EXTREFCNT_MEM_NAME	"mbuf_ext_refcnt"
 #define	MBUF_EXTPGS_MEM_NAME	"mbuf_extpgs"
 
-#ifdef _KERNEL
+#if defined(_KERNEL) || defined(_KERNEL_UT)
 union if_snd_tag_alloc_params;
 
 #ifdef WITNESS
@@ -1680,5 +1680,5 @@
 	return (false);
 }
 
-#endif /* _KERNEL */
+#endif /* _KERNEL || _KERNEL_UT */
 #endif /* !_SYS_MBUF_H_ */