diff --git a/frappe/core/doctype/doctype/doctype.py b/frappe/core/doctype/doctype/doctype.py
index f7c9cbe28a..7306f90108 100644
--- a/frappe/core/doctype/doctype/doctype.py
+++ b/frappe/core/doctype/doctype/doctype.py
@@ -893,7 +893,7 @@ def validate_fields(meta):
 			field.fetch_from = field.fetch_from.strip('\n').strip()
 
 	def validate_data_field_type(docfield):
-		if docfield.fieldtype == "Data":
+		if docfield.fieldtype == "Data" and not (docfield.oldfieldtype and docfield.oldfieldtype != "Data"):
 			if docfield.options and (docfield.options not in data_field_options):
 				df_str = frappe.bold(_(docfield.label))
 				text_str = _("{0} is an invalid Data field.").format(df_str) + "<br>" * 2 + _("Only Options allowed for Data field are:") + "<br>"