Noise from upstairs neighbor?

You're going to laugh at this one, but it is serious. My upstairs neighbor's bedroom is directly above mine. His bed CREAKS very loudly. It wakes me up every time he turns over in bed. Thank God he dosn't have a girlfriend! I've asked him to fix it and the noise stopped for awhile, but is back again. There is NO WAY that he can't hear it. Any suggestions? can I call the police for a squeeky bed?