That's a sign that you've been soloing and listening to standard rock pentatonics too much .
Whenever you improvise , you don't usualy have to come up with something entirely new , you just connect some pieces and tricks you know in some order that fits the progression to form musical lines.
Try to get yourself into different styles to add more tricks into your arsenal ... Even if you don't want to get out of pentatonics , you can try old blues and stuff , there are many ways to play pentatonics and still sound unique and cool.