Prevent xclip from running in background

[arget13]

When I close a terminal session where I have used xclip (an alias of xclip -sel c) it takes a little longer than usual to close the window, which I assume is due to the background process xclip.
Is there a way to prevent xclip from playing in the background and make it exit right after copying to X's clipboard?

[hwangcc23]

There is no X clipboard.

See this StackOverflow question for an explanation
See https://stackoverflow.com/questions/19254114/xclip-does-not-terminate-when-tracing-it.