diff --git a/src/Expr.cc b/src/Expr.cc
index ad6c18432c..f1407b4137 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -3884,7 +3884,7 @@ IntrusivePtr<Val> FlattenExpr::Fold(Val* v) const
 	return l;
 	}
 
-ScheduleTimer::ScheduleTimer(EventHandlerPtr arg_event, val_list* arg_args,
+ScheduleTimer::ScheduleTimer(const EventHandlerPtr& arg_event, val_list* arg_args,
                              double t, TimerMgr* arg_tmgr)
 	: Timer(t, TIMER_SCHEDULE),
 	  event(arg_event), args(std::move(*arg_args)), tmgr(arg_tmgr)
@@ -4844,8 +4844,8 @@ TraversalCode ListExpr::Traverse(TraversalCallback* cb) const
 	HANDLE_TC_EXPR_POST(tc);
 	}
 
-RecordAssignExpr::RecordAssignExpr(IntrusivePtr<Expr> record,
-                                   IntrusivePtr<Expr> init_list, int is_init)
+RecordAssignExpr::RecordAssignExpr(const IntrusivePtr<Expr>& record,
+                                   const IntrusivePtr<Expr>& init_list, int is_init)
 	{
 	const expr_list& inits = init_list->AsListExpr()->Exprs();
 
diff --git a/src/Expr.h b/src/Expr.h
index f341f5a9c4..e42c4a611b 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -738,7 +738,7 @@ protected:
 
 class ScheduleTimer : public Timer {
 public:
-	ScheduleTimer(EventHandlerPtr event, val_list* args, double t,
+	ScheduleTimer(const EventHandlerPtr& event, val_list* args, double t,
 			TimerMgr* tmgr);
 	~ScheduleTimer() override;
 
@@ -881,7 +881,7 @@ protected:
 
 class RecordAssignExpr : public ListExpr {
 public:
-	RecordAssignExpr(IntrusivePtr<Expr> record, IntrusivePtr<Expr> init_list, int is_init);
+	RecordAssignExpr(const IntrusivePtr<Expr>& record, const IntrusivePtr<Expr>& init_list, int is_init);
 };
 
 class CastExpr : public UnaryExpr {