diff --git a/pyHS100/smartbulb.py b/pyHS100/smartbulb.py
index 70b40bf2..8e8cb9af 100644
--- a/pyHS100/smartbulb.py
+++ b/pyHS100/smartbulb.py
@@ -94,7 +94,7 @@ class SmartBulb(SmartDevice):
         self._device_type = DeviceType.Bulb
         self._light_state = None
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_color(self) -> bool:
         """Whether the bulb supports color changes.
@@ -105,7 +105,7 @@ class SmartBulb(SmartDevice):
         sys_info = self.sys_info
         return bool(sys_info["is_color"])
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_dimmable(self) -> bool:
         """Whether the bulb supports brightness changes.
@@ -116,7 +116,7 @@ class SmartBulb(SmartDevice):
         sys_info = self.sys_info
         return bool(sys_info["is_dimmable"])
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_variable_color_temp(self) -> bool:
         """Whether the bulb supports color temperature changes.
@@ -128,7 +128,7 @@ class SmartBulb(SmartDevice):
         sys_info = self.sys_info
         return bool(sys_info["is_variable_color_temp"])
 
-    @property
+    @property  # type: ignore
     @requires_update
     def valid_temperature_range(self) -> Tuple[int, int]:
         """Return the device-specific white temperature range (in Kelvin).
@@ -149,7 +149,7 @@ class SmartBulb(SmartDevice):
         self._sys_info = await self.get_sys_info()
         self._light_state = await self.get_light_state()
 
-    @property
+    @property  # type: ignore
     @requires_update
     def light_state(self) -> Optional[Dict[str, Dict]]:
         """Query the light state."""
@@ -167,7 +167,7 @@ class SmartBulb(SmartDevice):
         await self.update()
         return light_state
 
-    @property
+    @property  # type: ignore
     @requires_update
     def hsv(self) -> Tuple[int, int, int]:
         """Return the current HSV state of the bulb.
@@ -228,7 +228,7 @@ class SmartBulb(SmartDevice):
         }
         await self.set_light_state(light_state)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def color_temp(self) -> int:
         """Return color temperature of the device.
@@ -264,7 +264,7 @@ class SmartBulb(SmartDevice):
         light_state = {"color_temp": temp}
         await self.set_light_state(light_state)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def brightness(self) -> int:
         """Return the current brightness.
@@ -295,7 +295,7 @@ class SmartBulb(SmartDevice):
         light_state = {"brightness": brightness}
         await self.set_light_state(light_state)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def state_information(self) -> Dict[str, Any]:
         """Return bulb-specific state information.
@@ -315,7 +315,7 @@ class SmartBulb(SmartDevice):
 
         return info
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_on(self) -> bool:
         """Return whether the device is on."""
@@ -330,7 +330,7 @@ class SmartBulb(SmartDevice):
         """Turn the bulb on."""
         await self.set_light_state({"on_off": 1})
 
-    @property
+    @property  # type: ignore
     @requires_update
     def has_emeter(self) -> bool:
         """Return that the bulb has an emeter."""
diff --git a/pyHS100/smartdevice.py b/pyHS100/smartdevice.py
index ae4bf1cc..6198c7fa 100755
--- a/pyHS100/smartdevice.py
+++ b/pyHS100/smartdevice.py
@@ -244,7 +244,7 @@ class SmartDevice:
         """
         self._sys_info = await self.get_sys_info()
 
-    @property
+    @property  # type: ignore
     @requires_update
     def sys_info(self) -> Dict[str, Any]:
         """Retrieve system information.
@@ -253,9 +253,10 @@ class SmartDevice:
         :rtype dict
         :raises SmartDeviceException: on error
         """
+        assert self._sys_info is not None
         return self._sys_info
 
-    @property
+    @property  # type: ignore
     @requires_update
     def model(self) -> str:
         """Return device model.
@@ -267,7 +268,7 @@ class SmartDevice:
         sys_info = self.sys_info
         return str(sys_info["model"])
 
-    @property
+    @property  # type: ignore
     @requires_update
     def alias(self) -> str:
         """Return device name (alias).
@@ -375,7 +376,7 @@ class SmartDevice:
         """
         return await self._query_helper("time", "get_timezone")
 
-    @property
+    @property  # type: ignore
     @requires_update
     def hw_info(self) -> Dict:
         """Return hardware information.
@@ -398,7 +399,7 @@ class SmartDevice:
         sys_info = self.sys_info
         return {key: sys_info[key] for key in keys if key in sys_info}
 
-    @property
+    @property  # type: ignore
     @requires_update
     def location(self) -> Dict:
         """Return geographical location.
@@ -420,7 +421,7 @@ class SmartDevice:
 
         return loc
 
-    @property
+    @property  # type: ignore
     @requires_update
     def rssi(self) -> Optional[int]:
         """Return WiFi signal strenth (rssi).
@@ -433,7 +434,7 @@ class SmartDevice:
             return int(sys_info["rssi"])
         return None
 
-    @property
+    @property  # type: ignore
     @requires_update
     def mac(self) -> str:
         """Return mac address.
@@ -579,7 +580,7 @@ class SmartDevice:
         """Turn off the device."""
         raise NotImplementedError("Device subclass needs to implement this.")
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_off(self) -> bool:
         """Return True if device is off.
@@ -593,7 +594,7 @@ class SmartDevice:
         """Turn device on."""
         raise NotImplementedError("Device subclass needs to implement this.")
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_on(self) -> bool:
         """Return if the device is on.
@@ -604,7 +605,7 @@ class SmartDevice:
         """
         raise NotImplementedError("Device subclass needs to implement this.")
 
-    @property
+    @property  # type: ignore
     @requires_update
     def state_information(self) -> Dict[str, Any]:
         """Return device-type specific, end-user friendly state information.
diff --git a/pyHS100/smartplug.py b/pyHS100/smartplug.py
index 1013cc60..2a50f47c 100644
--- a/pyHS100/smartplug.py
+++ b/pyHS100/smartplug.py
@@ -51,7 +51,7 @@ class SmartPlug(SmartDevice):
         self.emeter_type = "emeter"
         self._device_type = DeviceType.Plug
 
-    @property
+    @property  # type: ignore
     @requires_update
     def brightness(self) -> int:
         """Return current brightness on dimmers.
@@ -92,7 +92,7 @@ class SmartPlug(SmartDevice):
         else:
             raise ValueError("Brightness value %s is not valid." % value)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_dimmable(self):
         """Whether the switch supports brightness changes.
@@ -103,7 +103,7 @@ class SmartPlug(SmartDevice):
         sys_info = self.sys_info
         return "brightness" in sys_info
 
-    @property
+    @property  # type: ignore
     @requires_update
     def has_emeter(self):
         """Return whether device has an energy meter.
@@ -115,7 +115,7 @@ class SmartPlug(SmartDevice):
         features = sys_info["feature"].split(":")
         return "ENE" in features
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_on(self) -> bool:
         """Return whether device is on.
@@ -141,7 +141,7 @@ class SmartPlug(SmartDevice):
         await self._query_helper("system", "set_relay_state", {"state": 0})
         await self.update()
 
-    @property
+    @property  # type: ignore
     @requires_update
     def led(self) -> bool:
         """Return the state of the led.
@@ -161,7 +161,7 @@ class SmartPlug(SmartDevice):
         await self._query_helper("system", "set_led_off", {"off": int(not state)})
         await self.update()
 
-    @property
+    @property  # type: ignore
     @requires_update
     def on_since(self) -> datetime.datetime:
         """Return pretty-printed on-time.
@@ -180,7 +180,7 @@ class SmartPlug(SmartDevice):
 
         return datetime.datetime.now() - datetime.timedelta(seconds=on_time)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def state_information(self) -> Dict[str, Any]:
         """Return switch-specific state information.
diff --git a/pyHS100/smartstrip.py b/pyHS100/smartstrip.py
index f27c2578..2571c542 100755
--- a/pyHS100/smartstrip.py
+++ b/pyHS100/smartstrip.py
@@ -66,7 +66,7 @@ class SmartStrip(SmartPlug):
                 )
             )
 
-    @property
+    @property  # type: ignore
     @requires_update
     def is_on(self) -> bool:
         """Return if any of the outlets are on."""
@@ -101,13 +101,13 @@ class SmartStrip(SmartPlug):
         await self._query_helper("system", "set_relay_state", {"state": 0})
         await self.update()
 
-    @property
+    @property  # type: ignore
     @requires_update
     def on_since(self) -> datetime.datetime:
         """Return the maximum on-time of all outlets."""
         return max(plug.on_since for plug in self.plugs)
 
-    @property
+    @property  # type: ignore
     @requires_update
     def state_information(self) -> Dict[str, Any]:
         """Return strip-specific state information.