diff --git a/checks/check_airq.py b/checks/check_airq.py
index ce8e1bb..70c3d74 100755
--- a/checks/check_airq.py
+++ b/checks/check_airq.py
@@ -8,7 +8,7 @@ or
 - pip3 install git+https://git.ao-it.net/python/CO2Meter
 """
 
-__version__     = '0.3.2'
+__version__     = '0.3.3'
 __author__      = 'anima'
 
 # imports
@@ -161,7 +161,7 @@ class AirQCO2Resource(nagiosplugin.Resource):
         Returns:
             nagisplugin.Metric: metric elements
         """
-        return nagiosplugin.Metric(name='airq_co2', value=int(self.airq.co2), context='scalar_context')
+        return nagiosplugin.Metric(name='airq_co2', value=int(self.airq.co2), uom='ppm', context='scalar_context')
 
 
 class AirQTempResource(nagiosplugin.Resource):
@@ -174,7 +174,7 @@ class AirQTempResource(nagiosplugin.Resource):
         Returns:
             nagisplugin.Metric: metric elements
         """
-        return nagiosplugin.Metric(name='airq_temp', value=float(self.airq.temp), context='scalar_context')
+        return nagiosplugin.Metric(name='airq_temp', value=float(self.airq.temp), uom='°C', context='scalar_context')
 
 
 def parse_args() -> argparse.Namespace: