diff --git a/hyprlock.sh b/hyprlock.sh
index 696c57a..46e2b5d 100644
--- a/hyprlock.sh
+++ b/hyprlock.sh
@@ -5,7 +5,8 @@ unlockedMonitorYPositions=(0 0 0)
 lockedMonitorYPositions=(1080 1080 1080)
 
 monitors=$(hyprctl -j monitors)
-monitorIndices=$(seq 0 $(($(echo "$monitors" | jq length)-1)))
+tailMonitorIndex=$(($(echo "$monitors" | jq length)-1))
+monitorIndices=$(seq 0 $tailMonitorIndex)
 
 if [ "$1" == "" ]; then
 	monitorUnlocked=0
@@ -50,6 +51,18 @@ elif [ "$1" == "help" ] || [ "$1" == "-h" ] || [ "$1" == "-help" ] || [ "$1" ==
 	exit
 fi
 
+if ! [[ $1 =~ ^[0-9]+$ ]]; then
+	echo "Error: Invalid parameter value was provided."
+	echo "[monitor_id] must be an integer."
+	exit 1
+fi
+
+if [ $1 -lt 0 ] || [ $tailMonitorIndex -lt $1 ]; then
+	echo "Error: The provided [monitor_id] is out of range."
+	echo "[monitor_id] must be an integer from 0 to $tailMonitorIndex."
+	exit 2
+fi
+
 monitor=$(echo "$monitors" | jq -c ".[$1]")
 
 unlockedMonitorYPosition=${unlockedMonitorYPositions[$1]}