diff --git a/frappe/model/db_schema.py b/frappe/model/db_schema.py
index d71bff45a4..62f0643904 100644
--- a/frappe/model/db_schema.py
+++ b/frappe/model/db_schema.py
@@ -190,7 +190,7 @@ class DbTable:
 	def get_index_definitions(self):
 		ret = []
 		for key, col in self.columns.items():
-			if col.set_index and col.fieldtype in type_map and \
+			if col.set_index and not col.unique and col.fieldtype in type_map and \
 					type_map.get(col.fieldtype)[0] not in ('text', 'longtext'):
 				ret.append('index `' + key + '`(`' + key + '`)')
 		return ret