diff --git a/xarray/namedarray/core.py b/xarray/namedarray/core.py
index f13c7e8d2c6..4eed572cbd2 100644
--- a/xarray/namedarray/core.py
+++ b/xarray/namedarray/core.py
@@ -395,7 +395,7 @@ def copy(
         return self._copy(deep=deep, data=data)
 
     @property
-    def ndim(self) -> _IntOrUnknown:
+    def ndim(self) -> int:
         """
         Number of array dimensions.