diff --git a/pytential/qbx/__init__.py b/pytential/qbx/__init__.py
index 0b94f90b8ad45f736582f3e0b684226d11ebcbac..16814fec0e722a2082ad82649c09e10136ee6114 100644
--- a/pytential/qbx/__init__.py
+++ b/pytential/qbx/__init__.py
@@ -173,7 +173,7 @@ class QBXLayerPotentialSource(LayerPotentialSourceBase):
             performance_data_file=None,
 
             debug=_not_provided,
-            _refined_for_global_qbx=None,
+            _refined_for_global_qbx=_not_provided,
             target_stick_out_factor=_not_provided,
             ):