diff --git a/include/linux/compat.h b/include/linux/compat.h
index 6f110957cc97..ef5cd192784c 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -228,6 +228,7 @@ static inline int compat_timespec_compare(struct compat_timespec *lhs,
 asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp);
 
 extern int compat_printk(const char *fmt, ...);
+extern void sigset_from_compat(sigset_t *set, compat_sigset_t *compat);
 
 #endif /* CONFIG_COMPAT */
 #endif /* _LINUX_COMPAT_H */