diff --git a/lib/libthr/thread/thr_sig.c b/lib/libthr/thread/thr_sig.c
index a99395fd1b38..d2be9947ac12 100644
--- a/lib/libthr/thread/thr_sig.c
+++ b/lib/libthr/thread/thr_sig.c
@@ -737,4 +737,13 @@ _setcontext(const ucontext_t *ucp)
 	return __sys_setcontext(&uc);
 }
 
-__weak_reference(__sys_swapcontext, swapcontext);
+__weak_reference(_swapcontext, swapcontext);
+int
+_swapcontext(ucontext_t *oucp, const ucontext_t *ucp)
+{
+	ucontext_t uc;
+
+	(void) memcpy(&uc, ucp, sizeof(uc));
+	remove_thr_signals(&uc.uc_sigmask);
+	return __sys_swapcontext(oucp, &uc);
+}