diff --git a/pipekit/web/app.py b/pipekit/web/app.py
index 3174ab0..e8f227c 100644
--- a/pipekit/web/app.py
+++ b/pipekit/web/app.py
@@ -724,9 +724,13 @@ async def wizard_create(request: Request):
             raise HTTPException(400, "no columns selected")
 
         qualified_source = src_drv.qualified_table_name(table, **qvals)
+        # Alias quoting must use the SOURCE dialect — this query runs on the
+        # source. (The load maps columns by position, so the alias is cosmetic;
+        # using dest quoting here leaked e.g. SQL Server [brackets] into a
+        # Postgres source query.)
         select_list = ",\n  ".join(
             f"{src_drv.default_expression(c['source_type'], c['source_name'])} AS "
-            f"{dest_drv.quote_identifier(c['dest_name'])}"
+            f"{src_drv.quote_identifier(c['dest_name'])}"
             for c in chosen
         )
         source_query_override = (form.get("source_query") or "").strip()