Allowing elements to be dragged by middle mouse button click is commonly undesirable behavior, because it disables page scroll functionality. Replacing `if (event.rightClick) return;` with `if(event.event.buttons!=1) return;` in both **Drag.start** and **Sortables.start** works. <bountysource-plugin> --- Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/46721705-drag-disable-drag-by-middle-mouse-button?utm_campaign=plugin&utm_content=tracker%2F22069&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F22069&utm_medium=issues&utm_source=github). </bountysource-plugin>