diff --git a/frappe/desk/form/linked_with.py b/frappe/desk/form/linked_with.py
index e5192b1edb..39850c4a16 100644
--- a/frappe/desk/form/linked_with.py
+++ b/frappe/desk/form/linked_with.py
@@ -119,7 +119,7 @@ def _get_linked_doctypes(doctype):
 		if not dt in ret:
 			ret[dt] = {"get_parent": True}
 
-	for dt in ret.keys():
+	for dt in list(ret.keys()):
 		try:
 			doctype_module = load_doctype_module(dt)
 		except ImportError: