diff -upr sbcl-1.3.1.orig/src/runtime/undefineds.h sbcl-1.3.1/src/runtime/undefineds.h
--- sbcl-1.3.1.orig/src/runtime/undefineds.h	2016-04-05 21:14:39.191968400 +0200
+++ sbcl-1.3.1/src/runtime/undefineds.h	2016-04-05 21:15:37.872124518 +0200
@@ -152,9 +152,6 @@ F(shutdown)
 #if !defined(hpux) && !defined(SVR4) && !defined(LISP_FEATURE_X86)
 F(sigreturn)
 #endif
-#if !defined(SVR4)
-F(sigsetmask)
-#endif
 #if !defined(SVR4) && !defined(LISP_FEATURE_FREEBSD) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
 F(sigstack)
 F(sigvec)
diff -upr sbcl-1.3.1.orig/tools-for-build/ldso-stubs.lisp sbcl-1.3.1/tools-for-build/ldso-stubs.lisp
--- sbcl-1.3.1.orig/tools-for-build/ldso-stubs.lisp	2016-04-05 21:14:38.945301077 +0200
+++ sbcl-1.3.1/tools-for-build/ldso-stubs.lisp	2016-04-05 21:16:15.048781267 +0200
@@ -345,8 +345,6 @@ ldso_stub__ ## fct: ;                  \
                  '("sysctlbyname")
                  #!+os-provides-dladdr
                  '("dladdr")
-                 #!-sunos ;; !defined(SVR4)
-                 '("sigsetmask")
                  #!-android
                    '("nl_langinfo"
                      "getpagesize"