diff --git a/kernel/exit.c b/kernel/exit.c
index 93851bc..eb8da36 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -27,6 +27,7 @@
 #include <linux/mempolicy.h>
 #include <linux/cpuset.h>
 #include <linux/syscalls.h>
+#include <linux/signal.h>
 
 #include <asm/uaccess.h>
 #include <asm/unistd.h>
@@ -277,7 +278,7 @@
  */
 int allow_signal(int sig)
 {
-	if (sig < 1 || sig > _NSIG)
+	if (!valid_signal(sig) || sig < 1)
 		return -EINVAL;
 
 	spin_lock_irq(&current->sighand->siglock);
@@ -298,7 +299,7 @@
 
 int disallow_signal(int sig)
 {
-	if (sig < 1 || sig > _NSIG)
+	if (!valid_signal(sig) || sig < 1)
 		return -EINVAL;
 
 	spin_lock_irq(&current->sighand->siglock);