diff --git a/core/reactor.cc b/core/reactor.cc
index 1533223c68..2996fc5f55 100644
--- a/core/reactor.cc
+++ b/core/reactor.cc
@@ -1318,16 +1318,28 @@ void smp::pin(unsigned cpu_id) {
 #endif
 
 void smp::allocate_reactor() {
-    static thread_local std::unique_ptr<reactor> reactor_holder;
+    // we cannot just write "local_engin = new reactor" since reactor's constructor
+    // uses local_engine
+    struct set_local_engine {
+        set_local_engine(reactor * r) {
+            local_engine = r;
+        }
+        ~set_local_engine() {
+            local_engine = nullptr;
+        }
+    };
+    class local_reactor : private set_local_engine, public reactor {
+    public:
+        local_reactor()
+            : set_local_engine(this)
+        {}
+    };
+
+    static thread_local std::unique_ptr<local_reactor> reactor_holder;
 
     assert(!reactor_holder);
 
-    // we cannot just write "local_engin = new reactor" since reactor's constructor
-    // uses local_engine
-    auto buf = new (with_alignment(64)) char[sizeof(reactor)];
-    local_engine = reinterpret_cast<reactor*>(buf);
-    new (buf) reactor;
-    reactor_holder.reset(local_engine);
+    reactor_holder.reset(new local_reactor());
 }
 
 void smp::cleanup() {