--- a/.emacs-my	Mon Feb 20 15:52:38 2017 +0200
+++ b/.emacs-my	Mon Feb 20 15:56:22 2017 +0200
@@ -659,6 +659,7 @@
 
 ;; Default 'command-history' length too short (in Emacs 23.2 is 30).
 (setq history-length 200)
+(setq history-delete-duplicates t)
 
 ;; Don't beep in my headphones!
 (setq ring-bell-function '(lambda () "Empty ring-bell-function." nil))