diff --git a/pkg/proxystorage/proxy.go b/pkg/proxystorage/proxy.go
index e0da4064f..e5071056b 100644
--- a/pkg/proxystorage/proxy.go
+++ b/pkg/proxystorage/proxy.go
@@ -299,7 +299,7 @@ func (p *ProxyStorage) NodeReplacer(ctx context.Context, s *promql.EvalStmt, nod
 				Op: promql.ItemDIV,
 				LHS: &promql.AggregateExpr{
 					Op:       promql.ItemSum,
-					Expr:     n.Expr,
+					Expr:     CloneExpr(n.Expr),
 					Param:    n.Param,
 					Grouping: n.Grouping,
 					Without:  n.Without,
@@ -307,7 +307,7 @@ func (p *ProxyStorage) NodeReplacer(ctx context.Context, s *promql.EvalStmt, nod
 
 				RHS: &promql.AggregateExpr{
 					Op:       promql.ItemCount,
-					Expr:     n.Expr,
+					Expr:     CloneExpr(n.Expr),
 					Param:    n.Param,
 					Grouping: n.Grouping,
 					Without:  n.Without,
diff --git a/pkg/proxystorage/util.go b/pkg/proxystorage/util.go
index df56eac7f..b22f97299 100644
--- a/pkg/proxystorage/util.go
+++ b/pkg/proxystorage/util.go
@@ -110,3 +110,8 @@ func (f *BooleanFinder) Visit(node promql.Node, _ []promql.Node) (promql.Visitor
 	}
 	return f, nil
 }
+
+func CloneExpr(expr promql.Expr) (newExpr promql.Expr) {
+	newExpr, _ = promql.ParseExpr(expr.String())
+	return
+}