diff --git a/rpi-scripts/gui/gui-start.service b/rpi-scripts/gui/gui-start.service
index bf7a7c3..c8ac916 100644
--- a/rpi-scripts/gui/gui-start.service
+++ b/rpi-scripts/gui/gui-start.service
@@ -1,14 +1,24 @@
+# systemd service file for auto starting the python gui 
+# at the correct time after startup (when window manager finished starting)
+
+
+# Usage:
+#  - Install: `sudo cp rpi-scripts/gui/gui-start.service /etc/systemd/system/`
+#  - Enable autostart:  `sudo systemctl enable gui-start.service`
+#  - Disable autostart: `sudo systemctl disable gui-start.service`
+
 [Unit]
-Description=Start Python GUI on boot
-After=graphical.target
+Description=Start Python GUI for IO-control and monitoring after startup
+After=display-manager.service
+Wants=display-manager.service
 
 [Service]
 Environment=DISPLAY=:0
-ExecStart=/bin/python ./main.py
+ExecStart=/usr/bin/python3 /home/pi/git/rpi-interface-board/rpi-scripts/gui/main.py
 WorkingDirectory=/home/pi/git/rpi-interface-board/rpi-scripts/gui
 User=pi
 Group=pi
 Restart=always
 
 [Install]
-WantedBy=graphical.target
+WantedBy=default.target