diff --git a/src/os_unix.h b/src/os_unix.h
index 00ae239..d87ec90 100644
--- a/src/os_unix.h
+++ b/src/os_unix.h
@@ -88,21 +88,10 @@
 // have an argument???
 #define SIGHASARG
 
-// List 3 arg systems here. I guess __sgi, please test and correct me. jw.
-#if defined(__sgi) && defined(HAVE_SIGCONTEXT)
-# define SIGHAS3ARGS
-#endif
-
 #ifdef SIGHASARG
-# ifdef SIGHAS3ARGS
-#  define SIGPROTOARG	(int, int, struct sigcontext *)
-#  define SIGDEFARG(s)	(int s, int sig2, struct sigcontext *scont)
-#  define SIGDUMMYARG	0, 0, (struct sigcontext *)0
-# else
-#  define SIGPROTOARG	(int)
-#  define SIGDEFARG(s)	(int s UNUSED)
-#  define SIGDUMMYARG	0
-# endif
+# define SIGPROTOARG	(int)
+# define SIGDEFARG(s)	(int s UNUSED)
+# define SIGDUMMYARG	0
 #else
 # define SIGPROTOARG   (void)
 # define SIGDEFARG(s)  ()