diff --git a/frappe/custom/doctype/custom_field/custom_field.py b/frappe/custom/doctype/custom_field/custom_field.py
index bc325b654e..ee6e3b9c61 100644
--- a/frappe/custom/doctype/custom_field/custom_field.py
+++ b/frappe/custom/doctype/custom_field/custom_field.py
@@ -32,6 +32,7 @@ class CustomField(Document):
 		self.fieldname = self.fieldname.lower()
 
 	def before_insert(self):
+		self.set_fieldname()
 		meta = frappe.get_meta(self.dt, cached=False)
 		fieldnames = [df.fieldname for df in meta.get("fields")]