diff --git a/sys/sys/signal.h b/sys/sys/signal.h
index 8e4daa64f5d..ff52b64740f 100644
--- a/sys/sys/signal.h
+++ b/sys/sys/signal.h
@@ -110,6 +110,7 @@
 #endif
 #if __BSD_VISIBLE
 #define	SIGTHR		32	/* reserved by thread library. */
+#define	SIGLWP		SIGTHR
 #endif
 
 #define	SIGRTMIN	65