diff --git a/dns.go b/dns.go
index 9a9b0c07d..5546f1156 100644
--- a/dns.go
+++ b/dns.go
@@ -52,10 +52,9 @@ func (d *syncDNSClient) Set(client DNSClient) {
 		return
 	}
 
-	d.Close()
-
 	d.Lock()
 	defer d.Unlock()
 
+	common.Close(d.DNSClient)
 	d.DNSClient = client
 }
diff --git a/network.go b/network.go
index 3b1b721a5..3e36624b0 100644
--- a/network.go
+++ b/network.go
@@ -88,11 +88,10 @@ func (m *syncInboundHandlerManager) Set(manager InboundHandlerManager) {
 		return
 	}
 
-	m.Close()
-
 	m.Lock()
 	defer m.Unlock()
 
+	common.Close(m.InboundHandlerManager)
 	m.InboundHandlerManager = manager
 }
 
@@ -171,9 +170,9 @@ func (m *syncOutboundHandlerManager) Set(manager OutboundHandlerManager) {
 		return
 	}
 
-	m.Close()
 	m.Lock()
 	defer m.Unlock()
 
+	common.Close(m.OutboundHandlerManager)
 	m.OutboundHandlerManager = manager
 }
diff --git a/policy.go b/policy.go
index 4cb9b3979..52d84a8a7 100644
--- a/policy.go
+++ b/policy.go
@@ -87,10 +87,9 @@ func (m *syncPolicyManager) Set(manager PolicyManager) {
 		return
 	}
 
-	m.Close()
-
 	m.Lock()
 	defer m.Unlock()
 
+	common.Close(m.PolicyManager)
 	m.PolicyManager = manager
 }
diff --git a/router.go b/router.go
index bd1e2d814..6cbb3e792 100644
--- a/router.go
+++ b/router.go
@@ -58,10 +58,10 @@ func (d *syncDispatcher) Set(disp Dispatcher) {
 		return
 	}
 
-	d.Close()
 	d.Lock()
 	defer d.Unlock()
 
+	common.Close(d.Dispatcher)
 	d.Dispatcher = disp
 }
 
@@ -117,9 +117,9 @@ func (r *syncRouter) Set(router Router) {
 		return
 	}
 
-	r.Close()
 	r.Lock()
 	defer r.Unlock()
 
+	common.Close(r.Router)
 	r.Router = router
 }