Hello `prog-fill-reindent-defun' does not respect the value of fill-column when inside a string (e.g. a docstring) in emacs-lisp-mode and lisp-interaction-mode. I checked it is respected in python-mode, c-mode, and c++-mode. From emacs -Q: Yank into the *scratch* buffer: (defun a () "a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a" nil) C-x f 30 RET Put the point inside the docstring and M-q Observe that it is filled to something like column 70 to 75. Thanks Jake