From 5ab7c8e9bab6f8cc9a18d461db065bc9e689ad2c Mon Sep 17 00:00:00 2001
From: Daan Beverdam <daanbeverdam@users.noreply.github.com>
Date: Thu, 17 Nov 2022 21:57:26 +0100
Subject: [PATCH] Fix moving average for 0 values (#80476)

---
 homeassistant/components/filter/sensor.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/homeassistant/components/filter/sensor.py b/homeassistant/components/filter/sensor.py
index 4c9c83a8787..ce70ed14d19 100644
--- a/homeassistant/components/filter/sensor.py
+++ b/homeassistant/components/filter/sensor.py
@@ -612,7 +612,7 @@ class TimeSMAFilter(Filter, SensorEntity):
 
         moving_sum = 0
         start = new_state.timestamp - self._time_window
-        prev_state = self.last_leak or self.queue[0]
+        prev_state = self.last_leak if self.last_leak is not None else self.queue[0]
         for state in self.queue:
             moving_sum += (state.timestamp - start).total_seconds() * prev_state.state
             start = state.timestamp