diff --git a/pint/compat.py b/pint/compat.py
index 7264c35d1..25fafc240 100644
--- a/pint/compat.py
+++ b/pint/compat.py
@@ -147,6 +147,10 @@ def _to_magnitude(value, force_ndarray=False):
 
 
 def is_upcast_type(other):
+    """ check if the type object is a upcast type
+
+    :param other: type
+    """
     # Check if class name is in preset list
     return other.__name__ in ("PintArray", "Series", "DataArray")