diff --git a/wagtail/admin/views/mixins.py b/wagtail/admin/views/mixins.py
index 3e05d23dfe..e15ca6bde1 100644
--- a/wagtail/admin/views/mixins.py
+++ b/wagtail/admin/views/mixins.py
@@ -261,7 +261,7 @@ class SpreadsheetExportMixin:
                     model_class = queryset.model
                 except AttributeError:
                     return force_str(field)
-                
+
                 for model in relation:
                     foreign_field = model_class._meta.get_field(model)
                     model_class = foreign_field.related_model