diff --git a/panda/src/configfiles/panda.emacs b/panda/src/configfiles/panda.emacs
index 8bb8c94346..c76f4418b4 100644
--- a/panda/src/configfiles/panda.emacs
+++ b/panda/src/configfiles/panda.emacs
@@ -17,6 +17,12 @@
 	 ("\\.emacs$". lisp-mode)
 	 ) auto-mode-alist))
 
+; There's too much disagreement between different editors
+; (particularly Windows editors) over how many spaces a tab
+; represents.  Better not to put them any any source files at all.
+(custom-set-variables
+ '(indent-tabs-mode nil))
+
 ;;
 ;; Scheme customization
 ;;