diff --git a/yamahactrl.sh b/yamahactrl.sh
index 123df72..e0a5de4 100755
--- a/yamahactrl.sh
+++ b/yamahactrl.sh
@@ -1,8 +1,9 @@
-### CONFIG
+#!/bin/bash
 
+### CONFIG
 YAMAHA_IP="192.168.0.50"
-
 ### END CONFIG
+
 read_dom() {
     local IFS=\>
     read -d \< ENTITY CONTENT
@@ -17,11 +18,11 @@ get_volume() {
 }
 
 volume_up() {
-    set_volume "$(( $(get_volume) - 10 ))"
+    set_volume "$(( $(get_volume) + 10 ))"
 }
 
 volume_down() {
-    set_volume "$(( $(get_volume) + 10 ))"
+    set_volume "$(( $(get_volume) - 10 ))"
 }
 
 set_volume() {