diff --git a/install/lib/wallpaper.sh b/install/lib/wallpaper.sh
index 70db0bf..3dddd8c 100644
--- a/install/lib/wallpaper.sh
+++ b/install/lib/wallpaper.sh
@@ -64,7 +64,8 @@ write_hyprpaper_config() {
 
   # Back up any pre-existing non-empty config (unless it's already ours).
   if [[ -s $conf ]] && ! grep -q '^# Generated by dotfiles install/lib/wallpaper.sh' "$conf"; then
-    local backup="$conf.pre-install.$(date +%s)"
+    local backup
+    backup="$conf.pre-install.$(date +%s)"
     cp "$conf" "$backup"
     info "Backed up existing hyprpaper.conf -> $backup"
   fi