CommonPdf | Pdf utility library | Document Editor library

This should be simple but I am getting stuck somewhere.

I want to recurse through a directory and rename all pdfs the same filename. The renamed files should remain in their current subdirectory.

The current PDF filenames are arbitrary.

Assume that I am running this script from the top directory. Inside this top directory are several subdirs, each with a PDF with an arbitrary filename.

This works to rename the files in place:

find . -iname "*.pdf" -exec rename 's/test.pdf/commonname.pdf/' '{}' \;

But since the current filenames are arbitrary, I need to swap out a regex for "any characters or digits" in place of test.pdf

My understanding is that the correct regex expression is .*

So I tried:

find . -iname "*.pdf" -exec rename 's/.*/commonname.pdf/' '{}' \;

When I run this, the first PDF gets renamed to commonpdf.pdf, but it is moved into the top directory. My use case requires that the PDFs get renamed in place.

I am missing something obvious here, clearly - can you spot my mistake?