diff --git a/homeassistant/components/environment_canada/sensor.py b/homeassistant/components/environment_canada/sensor.py
index 1c9a6fa1709..8a734f74dd6 100644
--- a/homeassistant/components/environment_canada/sensor.py
+++ b/homeassistant/components/environment_canada/sensor.py
@@ -34,19 +34,11 @@ from .const import ATTR_STATION, DOMAIN
 ATTR_TIME = "alert time"
 
 
-@dataclass(frozen=True)
-class ECSensorEntityDescriptionMixin:
-    """Mixin for required keys."""
-
-    value_fn: Callable[[Any], Any]
-
-
-@dataclass(frozen=True)
-class ECSensorEntityDescription(
-    SensorEntityDescription, ECSensorEntityDescriptionMixin
-):
+@dataclass(frozen=True, kw_only=True)
+class ECSensorEntityDescription(SensorEntityDescription):
     """Describes Environment Canada sensor entity."""
 
+    value_fn: Callable[[Any], Any]
     transform: Callable[[Any], Any] | None = None