diff --git a/frappe/model/db_schema.py b/frappe/model/db_schema.py
index 376d2dee15..ff35518a24 100644
--- a/frappe/model/db_schema.py
+++ b/frappe/model/db_schema.py
@@ -119,7 +119,12 @@ class DbTable:
 
 				if max_length and max_length[0][0] > new_length:
 					current_type = self.current_columns[col.fieldname]["type"]
-					current_length = re.findall('varchar\(([\d]+)\)', current_type)[0]
+					current_length = re.findall('varchar\(([\d]+)\)', current_type)
+					if not current_length:
+						# case when the field is no longer a varchar
+						continue
+
+					current_length = current_length[0]
 
 					if col.fieldname in self.columns:
 						self.columns[col.fieldname].length = current_length