diff --git a/ncdu-install.sh b/ncdu-install.sh
old mode 100644
new mode 100755
index a5f3c55..51b8c0d
--- a/ncdu-install.sh
+++ b/ncdu-install.sh
@@ -1,10 +1,16 @@
 #!/bin/bash
+
+if which ncdu &>/dev/null; then
+    echo 'ncdu is already installed'
+    exit 0
+fi
+
 if [[ $UID -ne 0 ]]; then
     sudo /bin/bash "$0" "$@"
     exit $?
 fi
 
-#btrfs property set -ts / ro false
+# SteamOS's wrapper for: btrfs property set -ts / ro false
 steamos-readonly disable
 
 pacman-key --init
@@ -12,5 +18,5 @@ pacman-key --populate archlinux
 
 pacman -S ncdu
 
-#btrfs property set -ts / ro true
+# SteamOS's wrapper for: btrfs property set -ts / ro true
 steamos-readonly enable