using standard cells of multiple height

I'm using the library cells from a particular vendor, but unfortunately a clock mux standard cell is not available with the particular vendor. But a clock mux standard cell for the same process and technology is available with another vendor. I have to use this particular clock mux from the second vendor and all other standard cells from the first vendor. But the Standard cell height of first vendor is 3.29 and that of the clock mux of the second vendor is 3.69. Please guide me how to solve this issue.