diff --git a/libc/include/signal.h b/libc/include/signal.h
index bdda84f..5540847 100644
--- a/libc/include/signal.h
+++ b/libc/include/signal.h
@@ -114,6 +114,7 @@
 extern int sigpending(sigset_t *);
 extern int sigsuspend(const sigset_t *);
 extern int sigwait(const sigset_t *set, int *sig);
+extern int siginterrupt(int  sig, int  flag);
 
 extern int raise(int);
 extern int kill(pid_t, int);