diff --git a/dump.py b/dump.py
index b574e46..19fa7d5 100755
--- a/dump.py
+++ b/dump.py
@@ -28,6 +28,7 @@ LINES = [
   ('Generation', ilt.GetGeneration, ''),
   ('Firmware version', ilt.GetFirmwareVersion, ''),
   ('Serial number', ilt.GetSerialNumber, ''),
+  # No GetAuxSerialNumber, because it errors on my ILT1000-V02
   ('Controller temperature', ilt.GetControllerTempF, '°F'),
   ('Ambient temperature', ilt.GetAmbientTempF, '°F'),
   ('Date/time', ilt.GetDateTime, ''),
diff --git a/ilt1000.py b/ilt1000.py
index 3f67de1..88b6188 100755
--- a/ilt1000.py
+++ b/ilt1000.py
@@ -26,7 +26,6 @@ class Saturated(Error):
 
 # TODO commands:
 # eraselogdata
-# getauxserialno
 # getdarkmode
 # getfactorydark
 # getirradiance
@@ -98,6 +97,9 @@ class ILT1000(object):
   def GetSerialNumber(self):
     return self._SendCommand('getserialnumber')
 
+  def GetAuxSerialNumber(self):
+    return self._SendCommand('getauxserialno')
+
   def GetControllerTempF(self):
     return int(self._SendCommand('gettemp'))