diff --git a/drivers/char/vt_ioctl.c b/drivers/char/vt_ioctl.c
index 5d386f4..8971484 100644
--- a/drivers/char/vt_ioctl.c
+++ b/drivers/char/vt_ioctl.c
@@ -24,6 +24,7 @@
 #include <linux/major.h>
 #include <linux/fs.h>
 #include <linux/console.h>
+#include <linux/signal.h>
 
 #include <asm/io.h>
 #include <asm/uaccess.h>
@@ -641,7 +642,7 @@
 		extern int spawnpid, spawnsig;
 		if (!perm || !capable(CAP_KILL))
 		  return -EPERM;
-		if (arg < 1 || arg > _NSIG || arg == SIGKILL)
+		if (!valid_signal(arg) || arg < 1 || arg == SIGKILL)
 		  return -EINVAL;
 		spawnpid = current->pid;
 		spawnsig = arg;