diff --git a/custom_components/irrigation_unlimited/binary_sensor.py b/custom_components/irrigation_unlimited/binary_sensor.py
index c5dbb30..4265b6d 100644
--- a/custom_components/irrigation_unlimited/binary_sensor.py
+++ b/custom_components/irrigation_unlimited/binary_sensor.py
@@ -47,6 +47,7 @@
     RES_MANUAL,
     RES_NOT_RUNNING,
     RES_NONE,
+    ATTR_VOLUME,
 )
 
 
@@ -257,5 +258,5 @@ def extra_state_attributes(self):
             attr[ATTR_CONFIGURATION] = self._zone.configuration
         if self._zone.show_timeline:
             attr[ATTR_TIMELINE] = self._zone.timeline()
-        attr["volume"] = self._zone.volume.total
+        attr[ATTR_VOLUME] = self._zone.volume.total
         return attr
diff --git a/custom_components/irrigation_unlimited/const.py b/custom_components/irrigation_unlimited/const.py
index 38dfe5b..6a15d14 100644
--- a/custom_components/irrigation_unlimited/const.py
+++ b/custom_components/irrigation_unlimited/const.py
@@ -193,6 +193,7 @@
 ATTR_NEXT_TICK = "next_tick"
 ATTR_TICK_LOG = "tick_log"
 ATTR_SUSPENDED = "suspended"
+ATTR_VOLUME = "volume"
 
 # Resources
 RES_MANUAL = "Manual"