diff --git a/esphome/components/number/__init__.py b/esphome/components/number/__init__.py
index 73fbfd6e90..f45b8c024a 100644
--- a/esphome/components/number/__init__.py
+++ b/esphome/components/number/__init__.py
@@ -28,6 +28,7 @@ from esphome.const import (
     DEVICE_CLASS_DATA_RATE,
     DEVICE_CLASS_DATA_SIZE,
     DEVICE_CLASS_DISTANCE,
+    DEVICE_CLASS_DURATION,
     DEVICE_CLASS_EMPTY,
     DEVICE_CLASS_ENERGY,
     DEVICE_CLASS_ENERGY_STORAGE,
@@ -81,6 +82,7 @@ DEVICE_CLASSES = [
     DEVICE_CLASS_DATA_RATE,
     DEVICE_CLASS_DATA_SIZE,
     DEVICE_CLASS_DISTANCE,
+    DEVICE_CLASS_DURATION,
     DEVICE_CLASS_EMPTY,
     DEVICE_CLASS_ENERGY,
     DEVICE_CLASS_ENERGY_STORAGE,