diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index b68c22ba15..28b6a2c0a4 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -1602,7 +1602,6 @@ contain_leaked_vars_walker(Node *node, void *context)
 		case T_Var:
 		case T_Const:
 		case T_Param:
-		case T_ArrayRef:
 		case T_ArrayExpr:
 		case T_FieldSelect:
 		case T_FieldStore:
@@ -1643,6 +1642,23 @@ contain_leaked_vars_walker(Node *node, void *context)
 				return true;
 			break;
 
+		case T_ArrayRef:
+			{
+				ArrayRef *aref = (ArrayRef *) node;
+
+				/*
+				 * array assignment is leaky, but subscripted fetches
+				 * are not
+				 */
+				if (aref->refassgnexpr != NULL)
+				{
+					/* Node is leaky, so reject if it contains Vars */
+					if (contain_var_clause(node))
+						return true;
+				}
+			}
+			break;
+
 		case T_RowCompareExpr:
 			{
 				/*