diff --git a/src/panel/applets/icon-tasklist/IconTasklistApplet.vala b/src/panel/applets/icon-tasklist/IconTasklistApplet.vala
index 58dc6256e..7a3feb9ab 100644
--- a/src/panel/applets/icon-tasklist/IconTasklistApplet.vala
+++ b/src/panel/applets/icon-tasklist/IconTasklistApplet.vala
@@ -427,9 +427,18 @@ public class IconTasklistApplet : Budgie.Applet {
 		if (button == null) { // Button might be pinned, try to get button from launcher instead
 			app_id = group.get_desktop_id();
 			button = buttons.get(app_id);
+
+			// Because the only way to get a desktop_id from an application on X11 is basically
+			// to just guess, the casing may not be correct, e.g. Nemo.desktop vs nemo.desktop.
+			// Try again to get the button, this time making the desktop_id all lowercase.
+			if (button == null) {
+				app_id = app_id.down();
+				button = buttons.get(app_id);
+			}
 		}
 
 		if (button == null) { // we don't manage this button
+			warning(@"an application ($(group.group_id)) was closed, but we couldn't find its button");
 			return;
 		}
 
diff --git a/src/panel/applets/icon-tasklist/widgets/IconButton.vala b/src/panel/applets/icon-tasklist/widgets/IconButton.vala
index cd0e034c4..56c2db723 100644
--- a/src/panel/applets/icon-tasklist/widgets/IconButton.vala
+++ b/src/panel/applets/icon-tasklist/widgets/IconButton.vala
@@ -620,14 +620,14 @@ public class IconButton : Gtk.ToggleButton {
 	public void update() {
 		if (window_group != null && window_group.has_windows()) {
 			get_style_context().add_class("running");
-		} else {
+		} else if (window_group != null && !window_group.has_windows()) {
 			get_style_context().remove_class("running");
 
 			if (!pinned) return;
-			window_group = null;
 
 			var active_window = window_group?.get_active_window() ?? window_group?.get_last_active_window();
 			set_tooltip_text(app?.name ?? active_window?.get_name() ?? "");
+			window_group = null;
 		}
 
 		set_active(has_active_window);