diff --git a/@overflow/discovery/subscriber/discovery.subscriber.ts b/@overflow/discovery/subscriber/discovery.subscriber.ts
index e2fd39a..08d2abf 100644
--- a/@overflow/discovery/subscriber/discovery.subscriber.ts
+++ b/@overflow/discovery/subscriber/discovery.subscriber.ts
@@ -27,13 +27,10 @@ export class DiscoverySubscriber {
   public constructor(
     private loggerService: LoggerService,
   ) {
-    this.discoverySubscriberSubject = null;
+    this.discoverySubscriberSubject = new DiscoverySubscriberSubject();
   }
 
   public observable(): Observable<DiscoveryNotify> {
-    if (null === this.discoverySubscriberSubject) {
-      this.discoverySubscriberSubject = new DiscoverySubscriberSubject();
-    }
     return this.discoverySubscriberSubject.asObservable();
   }
 
diff --git a/@overflow/noauth-probe/subscriber/noauth-probe.subscriber.ts b/@overflow/noauth-probe/subscriber/noauth-probe.subscriber.ts
index 3226845..6b68937 100644
--- a/@overflow/noauth-probe/subscriber/noauth-probe.subscriber.ts
+++ b/@overflow/noauth-probe/subscriber/noauth-probe.subscriber.ts
@@ -23,13 +23,10 @@ export class NoAuthProbeSubscriber {
   public constructor(
     private loggerService: LoggerService,
   ) {
-    this.noAuthProbeSubscriberSubject = null;
+    this.noAuthProbeSubscriberSubject = new NoAuthProbeSubscriberSubject();
   }
 
   public observable(): Observable<NoAuthProbeNotify> {
-    if (null === this.noAuthProbeSubscriberSubject) {
-      this.noAuthProbeSubscriberSubject = new NoAuthProbeSubscriberSubject();
-    }
     return this.noAuthProbeSubscriberSubject.asObservable();
   }
 
@@ -37,14 +34,14 @@ export class NoAuthProbeSubscriber {
     this.noAuthProbeSubscriberSubject.next({ method: method, params: params });
   }
 
-  @RPCSubscriber({method: 'NoAuthProbeService.onConnect'})
+  @RPCSubscriber({ method: 'NoAuthProbeService.onConnect' })
   public onConnect(noAuthProbe: NoAuthProbe): void {
     this.loggerService.debug('NoAuthProbeService.onConnect noAuthProbe:', noAuthProbe);
 
     this.publish('NoAuthProbeService.onConnect', noAuthProbe);
   }
 
-  @RPCSubscriber({method: 'NoAuthProbeService.onDisconnect'})
+  @RPCSubscriber({ method: 'NoAuthProbeService.onDisconnect' })
   public onDisconnect(noAuthProbe: NoAuthProbe): void {
     this.loggerService.debug('NoAuthProbeService.onDisconnect noAuthProbe:', noAuthProbe);
 
diff --git a/@overflow/probe/subscriber/probe.subscriber.ts b/@overflow/probe/subscriber/probe.subscriber.ts
index 44f580a..de15dae 100644
--- a/@overflow/probe/subscriber/probe.subscriber.ts
+++ b/@overflow/probe/subscriber/probe.subscriber.ts
@@ -23,13 +23,10 @@ export class ProbeSubscriber {
   public constructor(
     private loggerService: LoggerService,
   ) {
-    this.probeSubscriberSubject = null;
+    this.probeSubscriberSubject = new ProbeSubscriberSubject();
   }
 
   public observable(): Observable<ProbeNotify> {
-    if (null === this.probeSubscriberSubject) {
-      this.probeSubscriberSubject = new ProbeSubscriberSubject();
-    }
     return this.probeSubscriberSubject.asObservable();
   }
 
@@ -37,14 +34,14 @@ export class ProbeSubscriber {
     this.probeSubscriberSubject.next({ method: method, params: params });
   }
 
-  @RPCSubscriber({method: 'ProbeService.onConnect'})
+  @RPCSubscriber({ method: 'ProbeService.onConnect' })
   public onConnect(probe: Probe): void {
     this.loggerService.debug('ProbeService.onConnect probe:', probe);
 
     this.publish('ProbeService.onConnect', probe);
   }
 
-  @RPCSubscriber({method: 'ProbeService.onDisconnect'})
+  @RPCSubscriber({ method: 'ProbeService.onDisconnect' })
   public onDisconnect(probe: Probe): void {
     this.loggerService.debug('ProbeService.onDisconnect noAuthProbe:', probe);