diff --git a/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/ChatRoomsHandler.kt b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/ChatRoomsHandler.kt
index f6f25e55d41facbd072ffe804a51e60675e10a0f..bd1f1b0bd263f81c495b33d29b493d18ed42758a 100644
--- a/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/ChatRoomsHandler.kt
+++ b/src/main/kotlin/de/thk/gm/websocketsdemo/handlers/ChatRoomsHandler.kt
@@ -53,9 +53,7 @@ class ChatRoomsHandler (private val chatRoomsService: ChatRoomsService, private
         var uri : UriComponents = UriComponentsBuilder.fromUri(session.uri!!).build()
         var id = uri.queryParams.getFirst("id")
         var sessions = hashMapOfSessions[id]
-        if(sessions != null) {
-            sessions.remove(session)
-        }
+        sessions?.remove(session)
     }
 
 }
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