diff --git a/homeassistant/components/obihai/sensor.py b/homeassistant/components/obihai/sensor.py
index b838d0ec92b..010b9780076 100644
--- a/homeassistant/components/obihai/sensor.py
+++ b/homeassistant/components/obihai/sensor.py
@@ -50,65 +50,37 @@ class ObihaiServiceSensors(SensorEntity):
     def __init__(self, pyobihai: PyObihai, serial: str, service_name: str) -> None:
         """Initialize monitor sensor."""
         self._service_name = service_name
-        self._state = None
-        self._name = f"{OBIHAI} {self._service_name}"
+        self._attr_name = f"{OBIHAI} {self._service_name}"
         self._pyobihai = pyobihai
-        self._unique_id = f"{serial}-{self._service_name}"
-
-    @property
-    def name(self):
-        """Return the name of the sensor."""
-        return self._name
-
-    @property
-    def native_value(self):
-        """Return the state of the sensor."""
-        return self._state
-
-    @property
-    def available(self):
-        """Return if sensor is available."""
-        if self._state is not None:
-            return True
-        return False
-
-    @property
-    def unique_id(self):
-        """Return the unique ID."""
-        return self._unique_id
-
-    @property
-    def device_class(self):
-        """Return the device class for uptime sensor."""
+        self._attr_unique_id = f"{serial}-{self._service_name}"
         if self._service_name == "Last Reboot":
-            return SensorDeviceClass.TIMESTAMP
-        return None
+            self._attr_device_class = SensorDeviceClass.TIMESTAMP
 
     @property
-    def icon(self):
+    def icon(self) -> str:
         """Return an icon."""
         if self._service_name == "Call Direction":
-            if self._state == "No Active Calls":
+            if self._attr_native_value == "No Active Calls":
                 return "mdi:phone-off"
-            if self._state == "Inbound Call":
+            if self._attr_native_value == "Inbound Call":
                 return "mdi:phone-incoming"
             return "mdi:phone-outgoing"
         if "Caller Info" in self._service_name:
             return "mdi:phone-log"
         if "Port" in self._service_name:
-            if self._state == "Ringing":
+            if self._attr_native_value == "Ringing":
                 return "mdi:phone-ring"
-            if self._state == "Off Hook":
+            if self._attr_native_value == "Off Hook":
                 return "mdi:phone-in-talk"
             return "mdi:phone-hangup"
         if "Service Status" in self._service_name:
             if "OBiTALK Service Status" in self._service_name:
                 return "mdi:phone-check"
-            if self._state == "0":
+            if self._attr_native_value == "0":
                 return "mdi:phone-hangup"
             return "mdi:phone-in-talk"
         if "Reboot Required" in self._service_name:
-            if self._state == "false":
+            if self._attr_native_value == "false":
                 return "mdi:restart-off"
             return "mdi:restart-alert"
         return "mdi:phone"
@@ -116,20 +88,25 @@ class ObihaiServiceSensors(SensorEntity):
     def update(self) -> None:
         """Update the sensor."""
         if not self._pyobihai.check_account():
-            self._state = None
+            self._attr_native_value = None
+            self._attr_available = False
             return
 
         services = self._pyobihai.get_state()
 
         if self._service_name in services:
-            self._state = services.get(self._service_name)
+            self._attr_native_value = services.get(self._service_name)
 
         services = self._pyobihai.get_line_state()
 
         if services is not None and self._service_name in services:
-            self._state = services.get(self._service_name)
+            self._attr_native_value = services.get(self._service_name)
 
         call_direction = self._pyobihai.get_call_direction()
 
         if self._service_name in call_direction:
-            self._state = call_direction.get(self._service_name)
+            self._attr_native_value = call_direction.get(self._service_name)
+
+        if self._attr_native_value is None:
+            self._attr_available = False
+        self._attr_available = True