diff --git a/sys/kern/subr_prf.c b/sys/kern/subr_prf.c
index 5886438fc48..e78863830c7 100644
--- a/sys/kern/subr_prf.c
+++ b/sys/kern/subr_prf.c
@@ -72,7 +72,11 @@ __FBSDID("$FreeBSD$");
  * Note that stdarg.h and the ANSI style va_start macro is used for both
  * ANSI and traditional C compilers.
  */
+#ifdef _KERNEL
 #include <machine/stdarg.h>
+#else
+#include <stdarg.h>
+#endif
 
 #ifdef _KERNEL