diff --git a/sway/sway-transparency.py b/sway/sway-transparency.py
index e153d8f..215ea14 100755
--- a/sway/sway-transparency.py
+++ b/sway/sway-transparency.py
@@ -30,7 +30,7 @@ def on_window_focus(opacity, ipc, event):
     focused = event.container
     workspace = focused_workspace.workspace().num
 
-    if focused.id != prev_focused.id:  # https://github.com/swaywm/sway/issues/2859
+    if prev_focused.id and focused.id != prev_focused.id:  # https://github.com/swaywm/sway/issues/2859
         focused.command("opacity 1")
         if workspace == prev_workspace and not prev_focused.sticky:
             prev_focused.command("opacity " + opacity)