diff --git a/pint_pandas/pint_array.py b/pint_pandas/pint_array.py
index 14b358a..486ce53 100644
--- a/pint_pandas/pint_array.py
+++ b/pint_pandas/pint_array.py
@@ -35,7 +35,6 @@
 # Magic 'unit' flagging columns with no unit support, used in
 # quantify/dequantify
 NO_UNIT = "No Unit"
-SUBDTYPES = True
 DEFAULT_SUBDTYPE = "Float64"
 
 pandas_version = version("pandas")