diff --git a/crm/api/doc.py b/crm/api/doc.py
index 9a2299ed..e09fd90e 100644
--- a/crm/api/doc.py
+++ b/crm/api/doc.py
@@ -95,15 +95,7 @@ def get_doctype_fields(doctype):
 	all_fields = []
 	all_fields.extend(fields)
 
-	# Add custom fields based on insert_after
-	for custom_field in custom_fields:
-		if custom_field.insert_after:
-			for i, field in enumerate(all_fields):
-				if field.fieldname == custom_field.insert_after:
-					all_fields.insert(i + 1, custom_field)
-					break
-		else:
-			all_fields.prepend(custom_field)
+	sort_custom_fields(custom_fields, all_fields)
 
 	sections = {}
 	section_fields = []
@@ -136,6 +128,25 @@ def get_doctype_fields(doctype):
 
 	return deal_fields
 
+def sort_custom_fields(custom_fields, all_fields):
+	# sort custom fields based on insert_after
+	not_in_fields = []
+	for custom_field in custom_fields:
+		if custom_field.insert_after:
+			field_exists = False
+			for i, field in enumerate(all_fields):
+				if field.fieldname == custom_field.insert_after:
+					all_fields.insert(i + 1, custom_field)
+					field_exists = True
+					break
+			if not field_exists:
+				not_in_fields.append(custom_field)
+		else:
+			all_fields.prepend(custom_field)
+
+	if not_in_fields:
+		sort_custom_fields(not_in_fields, all_fields)
+
 def get_field_obj(field):
 	obj = {
 		"label": field.label,