diff --git a/dstat_interface/main.py b/dstat_interface/main.py
index 6d296f5e33c52d6f7e9437fb19536c133bcc1613..926bf7ab7b4efba51718a6fb9e104c2de86ac1c6 100755
--- a/dstat_interface/main.py
+++ b/dstat_interface/main.py
@@ -257,6 +257,20 @@ class Main(object):
 
             dstat.comm.read_settings()
 
+            try:
+                if dstat.state.settings['dac_units_true'][1] != b'1':
+                    dstat.state.settings['dac_units_true'][1] = b'1'
+                    dstat.comm.write_settings()
+            except KeyError:
+                logger.warning("Connected DStat does not support sending DAC units.")
+                dialog = Gtk.MessageDialog(
+                    self.window, 0, Gtk.MessageType.WARNING,
+                    Gtk.ButtonsType.OK, "Connected DStat does not support sending DAC units." +
+                                        "Update firmware or set potentials will be incorrect!")
+
+                dialog.run()
+                dialog.destroy()
+
             self.start_ocp()
             self.connected = True
             self.serial_disconnect.set_sensitive(True)