diff --git a/homeassistant/components/filesize/sensor.py b/homeassistant/components/filesize/sensor.py
index 97fe5f5511d..22b8cd60d79 100644
--- a/homeassistant/components/filesize/sensor.py
+++ b/homeassistant/components/filesize/sensor.py
@@ -137,9 +137,10 @@ class FileSizeCoordinator(DataUpdateCoordinator):
             raise UpdateFailed(f"Can not retrieve file statistics {error}") from error
 
         size = statinfo.st_size
-        last_updated = datetime.fromtimestamp(statinfo.st_mtime).replace(
+        last_updated = datetime.utcfromtimestamp(statinfo.st_mtime).replace(
             tzinfo=dt_util.UTC
         )
+
         _LOGGER.debug("size %s, last updated %s", size, last_updated)
         data: dict[str, int | float | datetime] = {
             "file": round(size / 1e6, 2),