diff --git a/completion.bash b/completion.bash
new file mode 100644
index 00000000..dc16a05e
--- /dev/null
+++ b/completion.bash
@@ -0,0 +1,30 @@
+_setup_bench_tab_completion () {
+	if [ -n "$BASH" ] ; then
+        _bench () {
+			local cur=${COMP_WORDS[COMP_CWORD]}
+			local prev=${COMP_WORDS[COMP_CWORD-1]}
+			if [[ $prev == "--site" ]]; then
+				COMPREPLY=( $(compgen -W "`_site_dirs`" -- $cur) )
+			fi
+			}
+			complete -F _bench bench
+	elif [ -n "$ZSH_VERSION" ]; then
+		 _bench () {
+			 local a
+			 local prev
+			 read -l a
+			 prev=`echo $a| awk '{ print $NF }'`
+			 if [[ $prev == "--site" ]]; then
+				 reply=($(_site_dirs))
+			 fi
+         }
+		 compctl -K _bench bench
+	fi
+}
+
+_site_dirs() {
+	ls -d sites/*/ | sed "s/sites\///g" | sed "s/\/$//g" | xargs echo
+}
+
+
+_setup_bench_tab_completion