diff --git a/product/ERP5Form/ListBox.py b/product/ERP5Form/ListBox.py
index 35727a9390966811dfa0009be0a94231e9c2dc70..3d6e69714daf2fbb59a2b49cc4729a69bcbfb16e 100644
--- a/product/ERP5Form/ListBox.py
+++ b/product/ERP5Form/ListBox.py
@@ -1257,7 +1257,7 @@ class ListBoxRenderer:
         params.setdefault('meta_type', meta_type_list)
 
       # Remove FileUpload parameters
-      for k, v in params.items():
+      for k, v in list(params.items()):
         if k == "listbox":
           # listbox can also contain useless parameters
           new_list = []