--- a/include/u.h
+++ b/include/u.h
@@ -45,7 +45,7 @@ extern "C" {
 #	define _XOPEN_SOURCE 1000
 #	define _XOPEN_SOURCE_EXTENDED 1
 #endif
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 #	include <sys/cdefs.h>
 	/* for strtoll */
 #	undef __ISO_C_VISIBLE
--- a/src/cmd/dist/unix.c
+++ b/src/cmd/dist/unix.c
@@ -653,7 +653,7 @@ main(int argc, char **argv)
 		gohostarch = "amd64";
 #elif defined(__linux__)
 	gohostos = "linux";
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
 	gohostos = "freebsd";
 #elif defined(__OpenBSD__)
 	gohostos = "openbsd";
--- a/src/lib9/dirfwstat.c
+++ b/src/lib9/dirfwstat.c
@@ -29,7 +29,7 @@ THE SOFTWARE.
 #include <sys/time.h>
 #include <sys/stat.h>
 
-#if defined(__FreeBSD__) || defined(__APPLE__) || defined(__OpenBSD__) || defined(__linux__)
+#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__APPLE__) || defined(__OpenBSD__) || defined(__linux__)
 /* do nothing -- futimes exists and is fine */
 
 #elif defined(__SunOS5_9__)