diff --git a/Telegram/SourceFiles/platform/mac/overlay_widget_mac.mm b/Telegram/SourceFiles/platform/mac/overlay_widget_mac.mm
index 84892cf879..914525fe20 100644
--- a/Telegram/SourceFiles/platform/mac/overlay_widget_mac.mm
+++ b/Telegram/SourceFiles/platform/mac/overlay_widget_mac.mm
@@ -93,6 +93,18 @@ void MacOverlayWidgetHelper::updateStyles(bool fullscreen) {
 		? NSNormalWindowLevel
 		: NSPopUpMenuWindowLevel;
 	[window setLevel:level];
+
+	// Fullscreen overlay: follow the currently active Space on activation.
+	// Windowed overlay: behave like a normal tool panel, so the user can move
+	// it to another desktop and it stays there.
+	auto behavior = [window collectionBehavior];
+	if (fullscreen) {
+		behavior |= NSWindowCollectionBehaviorMoveToActiveSpace;
+	} else {
+		behavior &= ~NSWindowCollectionBehaviorMoveToActiveSpace;
+	}
+	[window setCollectionBehavior:behavior];
+
 	[window setHidesOnDeactivate:!_data->window->testAttribute(Qt::WA_MacAlwaysShowToolWindow)];
 	[window setTitleVisibility:NSWindowTitleHidden];
 	[window setTitlebarAppearsTransparent:YES];
diff --git a/Telegram/lib_ui b/Telegram/lib_ui
index fc740b2341..482e2dc1fd 160000
--- a/Telegram/lib_ui
+++ b/Telegram/lib_ui
@@ -1 +1 @@
-Subproject commit fc740b234111115a245b75a65bfb193d3b358695
+Subproject commit 482e2dc1fd94d3d2ca3f6e666499c647b0b67aba