diff --git a/mach/sun2/libsys/sigvec.c b/mach/sun2/libsys/sigvec.c
index d3e9205d..82a2e69d 100644
--- a/mach/sun2/libsys/sigvec.c
+++ b/mach/sun2/libsys/sigvec.c
@@ -3,6 +3,7 @@
 struct sigvec { int (*handler)(); int mask,flags; };
 int (*(_sigfunc[32]))();
 extern int _sigtramp();
+extern int errno;
 
 sigvec(sig,vec,ovec)
 	register struct sigvec *vec;
diff --git a/mach/sun3/libsys/sigvec.c b/mach/sun3/libsys/sigvec.c
index d3e9205d..82a2e69d 100644
--- a/mach/sun3/libsys/sigvec.c
+++ b/mach/sun3/libsys/sigvec.c
@@ -3,6 +3,7 @@
 struct sigvec { int (*handler)(); int mask,flags; };
 int (*(_sigfunc[32]))();
 extern int _sigtramp();
+extern int errno;
 
 sigvec(sig,vec,ovec)
 	register struct sigvec *vec;