diff --git a/switch-theme.sh b/switch-theme.sh
index dcd2163..5cfb9d7 100755
--- a/switch-theme.sh
+++ b/switch-theme.sh
@@ -17,6 +17,7 @@ define swap_dialog
 	read -p "Switch to theme: " num ; \
 	if [ ! -z $${num} -a $${num} -ge 1 -a -le $${n_themes} ] ; then \
 	  NEW_THEME=$$($(themes) | head -n$${num} | tail -n1 ) ; \
+    mv --backup=numbered rc.lua rc.lua.previous ; \
 	  cp $${NEW_THEME} rc.lua ; \
 	  echo "Theme is now $${NEW_THEME}"; \
   else echo " !! Aborted. " ; fi