--- a/zshrc	Tue Jan 10 04:24:43 2012 +0100
+++ b/zshrc	Thu Jan 26 16:32:35 2012 +0100
@@ -11,8 +11,12 @@
 fi
 
 # get rid of some unwanted aliases from the oh-my-zsh env
-unalias l
-unalias lsa
+if [ "`alias | grep 'l='`" != "" ]; then
+    unalias l
+fi
+if [ "`alias | grep 'lsa='`" != "" ]; then
+    unalias lsa
+fi
 
 # custom function that should work on all platforms
 cd() { builtin cd "$@"; print -D $PWD; }