diff --git a/README.md b/README.md
index 8b026fa..fa25906 100644
--- a/README.md
+++ b/README.md
@@ -220,6 +220,8 @@ Optionally set up a cronjob:
 ```
 $ cd rootfs/  # on SD card
 $ sudo touch var/spool/cron/crontabs/pi
+$ sudo chmod u=rw,og= var/spool/cron/crontabs/pi
+$ sudo chown pi:crontab var/spool/cron/crontabs/pi
 ```
 
 Edit `var/spool/cron/crontabs/pi` (optional):
@@ -301,3 +303,9 @@ $ sudo lpadmin -p dymo -v `sudo lpinfo -v | grep DYMO | cut -d" " -f2` -m 'dymo:
 $ sudo cupsenable dymo
 $ sudo cupsaccept dymo
 ```
+
+Test the printer:
+
+```
+$ echo "hello world" | lp -d dymo -
+```
diff --git a/main.py b/main.py
index 37bc2be..e622b4d 100755
--- a/main.py
+++ b/main.py
@@ -216,7 +216,7 @@ def print_nametag(name, guest=False):
     draw.text((x, y), quote, font=font, fill='black')
 
     im.save('tmp.png')
-    os.system('lp -d dymo tmp.png 2> /dev/null')
+    os.system('lp -d dymo tmp.png > /dev/null 2>&1')
 
 
 def message_protovac(message):