diff --git a/superset/connectors/sqla/models.py b/superset/connectors/sqla/models.py
index 1f68dea2be..83abc27c27 100644
--- a/superset/connectors/sqla/models.py
+++ b/superset/connectors/sqla/models.py
@@ -338,8 +338,7 @@ class TableColumn(Model, BaseColumn, CertificationMixin):
         ],
     ) -> str:
         """Convert datetime object to a SQL expression string"""
-        dttm_type = self.type or ("DATETIME" if self.is_dttm else None)
-        sql = self.db_engine_spec.convert_dttm(dttm_type, dttm) if dttm_type else None
+        sql = self.db_engine_spec.convert_dttm(self.type, dttm) if self.type else None
 
         if sql:
             return sql