diff --git a/trytond/backend/mysql/database.py b/trytond/backend/mysql/database.py
index a4775226c7..89c94fa9e9 100644
--- a/trytond/backend/mysql/database.py
+++ b/trytond/backend/mysql/database.py
@@ -289,7 +289,7 @@ class Cursor(CursorInterface):
         self.cursor.execute('FLUSH TABLES WITH READ LOCK')
 
     def has_constraint(self):
-        return True
+        return False
 
     def limit_clause(self, select, limit=None, offset=None):
         if offset and limit is None: