diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index f992646ca28..57f0ac83aaa 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -2773,6 +2773,7 @@ transformPLAssignStmt(ParseState *pstate, PLAssignStmt *stmt)
 											qry->sortClause,
 											EXPR_KIND_GROUP_BY,
 											false /* allow SQL92 rules */ );
+	qry->groupDistinct = sstmt->groupDistinct;
 
 	if (sstmt->distinctClause == NIL)
 	{