Changing my hotspot password doesn't require devices to enter new password.

Hi- I am using an iPhone 6 with the latest iOS. I use the personal hotspot quite often at coffee shops and I've realized (after letting a friend connect his computer to my hotspot) that changing the hotspot password on my phone does not prompt devices that previously connected to re-enter the new password. For example, if my original hotspot password was "FirstPassword" and I used it to connect, after changing the password to "SecondPassword" my Macbook simply gets disconnected from the Wifi connection but quickly reconnects without needing to enter the new password. I do know that the new password works because I CAN connect new devices using the new password. Does anyone have any suggestions so that I can prevent devices with the old password from connecting without needing the new password?