diff --git a/sys/sys/unistd.h b/sys/sys/unistd.h
index 2addb71611e7..1fcd38448559 100644
--- a/sys/sys/unistd.h
+++ b/sys/sys/unistd.h
@@ -61,7 +61,7 @@
 #define	_POSIX_MEMLOCK			-1
 #define	_POSIX_MEMLOCK_RANGE		200112L
 #define	_POSIX_MEMORY_PROTECTION	200112L
-#define	_POSIX_MESSAGE_PASSING		-1
+#define	_POSIX_MESSAGE_PASSING		200112L
 #define	_POSIX_MONOTONIC_CLOCK		200112L
 #define	_POSIX_NO_TRUNC			1
 #define	_POSIX_PRIORITIZED_IO		-1