diff --git a/src/Main.gd b/src/Main.gd
index 8e474e3..eed1b4f 100644
--- a/src/Main.gd
+++ b/src/Main.gd
@@ -121,8 +121,13 @@ func handle_backup() -> void:
 
 
 func _notification(what : int) -> void:
-	if what == MainLoop.NOTIFICATION_WM_QUIT_REQUEST: # Handle exit
-		show_quit_dialog()
+	match what:
+		MainLoop.NOTIFICATION_WM_QUIT_REQUEST: # Handle exit
+			show_quit_dialog()
+		MainLoop.NOTIFICATION_WM_FOCUS_OUT: # Called when the mouse isn't in the window anymore
+			Engine.set_target_fps(1) # then set the fps to 1 to relieve the cpu
+		MainLoop.NOTIFICATION_WM_MOUSE_ENTER: # Opposite of the above
+			Engine.set_target_fps(0) # 0 stands for maximum fps
 
 
 func _on_files_dropped(_files : PoolStringArray, _screen : int) -> void: