diff --git a/dotfiles/picom.conf b/dotfiles/picom.conf
index f686022..4921a71 100644
--- a/dotfiles/picom.conf
+++ b/dotfiles/picom.conf
@@ -11,6 +11,7 @@ use-ewmh-active-win = true;
 #  https://github.com/yshui/picom/issues/625
 opacity-rule = [
   "0:_NET_WM_STATE@[*]:32a = '_NET_WM_STATE_HIDDEN'",
+  # GTK frame extents are used for client-side shadows, we shouldn't have that as i3 does not support them.
   "100:_GTK_FRAME_EXTENTS@:c",
   "100:fullscreen",
   "100:name = 'Zoom Meeting'",
@@ -61,6 +62,7 @@ wintypes:
 };
 shadow-exclude = [
   "_NET_WM_STATE@[*]:32a = '_NET_WM_STATE_HIDDEN'",
+  # GTK frame extents are used for client-side shadows, we shouldn't have that.
   "_GTK_FRAME_EXTENTS@:c",
   "class_i = 'xss-dimmer'",
   "class_i = 'i3-frame'",