diff --git a/src/textual/widgets/_header.py b/src/textual/widgets/_header.py
index ddff8bc6c..ad2d5311e 100644
--- a/src/textual/widgets/_header.py
+++ b/src/textual/widgets/_header.py
@@ -125,6 +125,7 @@ class Header(Widget):
     DEFAULT_CLASSES = ""
 
     tall = Reactive(False)
+    """Track if the `Header` is in a tall state or not."""
 
     def __init__(
         self,