--- lib/libxview/notify/ndet.h.orig	1993-06-29 07:18:12.000000000 +0200
+++ lib/libxview/notify/ndet.h	2003-12-30 01:31:12.000000000 +0100
@@ -17,6 +17,11 @@
 #ifndef	NDET_DEFINED
 #define	NDET_DEFINED
 
+#include <sys/param.h>
+#if (defined(BSD) && (BSD >= 199103))
+#include <signal.h>
+#endif
+
 /*
 ********************** Detector Loop Notes ****************************
 Here is some notes on the detector loop:
