diff --git a/swayidle-lock-screen b/swayidle-lock-screen
index c900d8e..88daa63 100755
--- a/swayidle-lock-screen
+++ b/swayidle-lock-screen
@@ -1,6 +1,12 @@
 #!/usr/bin/env zsh
 
+LOCKFILE="${HOME}/.cache/swayidle-lock-screen.lock"
+
 function run {
+    # ensure multiple instances do not run
+    mkdir -p "$(dirname "${LOCKFILE}")"
+    exec 4<>"${LOCKFILE}"
+    flock -n 4 || exit 0
     dunstctl set-paused true
     swayidle -w -C /dev/null \
         timeout 15 'hyprctl dispatch dpms off' resume 'hyprctl dispatch dpms on' &
@@ -10,6 +16,7 @@ function run {
     hyprctl dispatch dpms on
     dunstctl set-paused false
     fix_eww
+    flock -u 4
 }
 
 function fix_eww {