diff --git a/custom_components/solarman/sensor.py b/custom_components/solarman/sensor.py
index 10e931d..40d41a5 100644
--- a/custom_components/solarman/sensor.py
+++ b/custom_components/solarman/sensor.py
@@ -196,7 +196,7 @@ def update(self):
                 self.p_state = val[self._field_name]
             else:
                 uom = getattr(self, 'uom', None)
-                if uom and (re.match("\S+", uom)):
+                if uom and (re.match(r"\S+", uom)):
                     self.p_state = None
                 _LOGGER.debug(f'No value recorded for {self._field_name}')