diff --git a/drivers/staging/comedi/drivers/dt2801.c b/drivers/staging/comedi/drivers/dt2801.c
index 3f365aee4822..83fb6e56c3e9 100644
--- a/drivers/staging/comedi/drivers/dt2801.c
+++ b/drivers/staging/comedi/drivers/dt2801.c
@@ -472,7 +472,7 @@ static const struct comedi_lrange *dac_range_table[] = {
 
 static const struct comedi_lrange *dac_range_lkup(int opt)
 {
-	if (opt < 0 || opt > 5)
+	if (opt < 0 || opt >= 5)
 		return &range_unknown;
 	return dac_range_table[opt];
 }