diff --git a/drivers/media/dvb/ttpci/av7110_ca.c b/drivers/media/dvb/ttpci/av7110_ca.c
index c58e3fc..1e89adc 100644
--- a/drivers/media/dvb/ttpci/av7110_ca.c
+++ b/drivers/media/dvb/ttpci/av7110_ca.c
@@ -277,7 +277,7 @@ static int dvb_ca_ioctl(struct inode *inode, struct file *file,
 	{
 		ca_slot_info_t *info=(ca_slot_info_t *)parg;
 
-		if (info->num > 1)
+		if (info->num < 0 || info->num > 1)
 			return -EINVAL;
 		av7110->ci_slot[info->num].num = info->num;
 		av7110->ci_slot[info->num].type = FW_CI_LL_SUPPORT(av7110->arm_app) ?