diff --git a/configuration.org b/configuration.org
index 5a7ab69684c38696ddc2dfee23c67645e89b41f7..4c3425b74b7b06f100b06c9b9edea32d932e6bbd 100644
--- a/configuration.org
+++ b/configuration.org
@@ -348,11 +348,11 @@ https://emacs-fu.blogspot.com/2008/12/zooming-inout.html
 #+begin_src emacs-lisp
 (defun my/text-zoom (n)
   "with positive N, increase the font size, otherwise decrease it"
-  (set-face-attribute 'default nil :height 
+  (set-face-attribute 'default (selected-frame) :height 
                       (+ (face-attribute 'default :height) (* (if (> n 0) 1 -1) 10)))
-  (set-face-attribute 'fixed-pitch nil :height 
+  (set-face-attribute 'fixed-pitch (selected-frame) :height 
                       (+ (face-attribute 'fixed-pitch :height) (* (if (> n 0) 1 -1) 10)))
-  (set-face-attribute 'variable-pitch nil :height 
+  (set-face-attribute 'variable-pitch (selected-frame) :height 
                       (+ (face-attribute 'variable-pitch :height) (* (if (> n 0) 1 -1) 10)))
   )