diff --git a/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/http/WebSocket.java b/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/http/WebSocket.java
index 2b13292c024..5b69b004fc6 100644
--- a/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/http/WebSocket.java
+++ b/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/http/WebSocket.java
@@ -21,44 +21,58 @@
 import java.util.concurrent.CompletableFuture;
 
 public interface WebSocket {
-  
+
   public interface Listener {
-    
-    default void onOpen(WebSocket webSocket) { }
-    
-    default void onMessage(WebSocket webSocket, String text) {}
-    
-    default void onMessage(WebSocket webSocket, ByteBuffer bytes) {}
-    
-    default void onClose(WebSocket webSocket, int code, String reason) {}
-    
-    default void onError(WebSocket webSocket, Throwable error) {}
-    
+
+    default void onOpen(WebSocket webSocket) {
+    }
+
+    default void onMessage(WebSocket webSocket, String text) {
+    }
+
+    default void onMessage(WebSocket webSocket, ByteBuffer bytes) {
+    }
+
+    default void onClose(WebSocket webSocket, int code, String reason) {
+    }
+
+    default void onError(WebSocket webSocket, Throwable error) {
+    }
+
   }
-  
+
   public interface Builder extends BasicBuilder {
-    
+
+    /**
+     * Builds a new WebSocket connection and waits asynchronously until the connection is opened.
+     * The listener onOpen callback is called before the returned future is completed.
+     *
+     * @param listener
+     * @return CompletableFuture which is completed after connection is opened
+     */
     CompletableFuture<WebSocket> buildAsync(Listener listener);
 
     @Override
     Builder header(String name, String value);
-    
+
     @Override
     Builder setHeader(String k, String v);
-    
+
     @Override
     Builder uri(URI uri);
-    
+
   }
 
   /**
    * Send some data
+   *
    * @return true if the message was successfully enqueued.
    */
   boolean send(ByteBuffer buffer);
-  
+
   /**
    * Send a close message
+   *
    * @return true if the message was successfully enqueued.
    */
   boolean sendClose(int code, String reason);
@@ -68,5 +82,5 @@ public interface Builder extends BasicBuilder {
    * doesn't include framing overhead.
    */
   long queueSize();
-  
+
 }
diff --git a/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/okhttp/OkHttpWebSocketImpl.java b/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/okhttp/OkHttpWebSocketImpl.java
index 64bcb774a9c..20fa45122b2 100644
--- a/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/okhttp/OkHttpWebSocketImpl.java
+++ b/kubernetes-client/src/main/java/io/fabric8/kubernetes/client/okhttp/OkHttpWebSocketImpl.java
@@ -32,16 +32,16 @@
 import java.util.concurrent.CompletableFuture;
 
 class OkHttpWebSocketImpl implements WebSocket {
-  
+
   static class BuilderImpl implements WebSocket.Builder {
-    
+
     private Request.Builder builder = new Request.Builder();
     private OkHttpClient httpClient;
 
     public BuilderImpl(OkHttpClient httpClient) {
       this.httpClient = httpClient;
     }
-    
+
     @Override
     public Builder uri(URI uri) {
       builder.url(HttpUrl.get(uri));
@@ -53,8 +53,8 @@ public CompletableFuture<WebSocket> buildAsync(Listener listener) {
       Request request = builder.build();
       CompletableFuture<WebSocket> future = new CompletableFuture<>();
       httpClient.newWebSocket(request, new WebSocketListener() {
-        private volatile boolean opened; 
-        
+        private volatile boolean opened;
+
         @Override
         public void onFailure(okhttp3.WebSocket webSocket, Throwable t, Response response) {
           if (response != null) {
@@ -63,10 +63,11 @@ public void onFailure(okhttp3.WebSocket webSocket, Throwable t, Response respons
           if (!opened) {
             if (response != null) {
               try {
-                future.completeExceptionally(new WebSocketHandshakeException(new OkHttpResponseImpl<>(response, null)).initCause(t));
+                future.completeExceptionally(
+                    new WebSocketHandshakeException(new OkHttpResponseImpl<>(response, null)).initCause(t));
               } catch (IOException e) {
                 // can't happen
-              } 
+              }
             } else {
               future.completeExceptionally(t);
             }
@@ -74,7 +75,7 @@ public void onFailure(okhttp3.WebSocket webSocket, Throwable t, Response respons
             listener.onError(new OkHttpWebSocketImpl(webSocket), t);
           }
         }
-        
+
         @Override
         public void onOpen(okhttp3.WebSocket webSocket, Response response) {
           opened = true;
@@ -82,25 +83,25 @@ public void onOpen(okhttp3.WebSocket webSocket, Response response) {
             response.close();
           }
           OkHttpWebSocketImpl value = new OkHttpWebSocketImpl(webSocket);
-          future.complete(value);
           listener.onOpen(value);
+          future.complete(value);
         }
-        
+
         @Override
         public void onMessage(okhttp3.WebSocket webSocket, ByteString bytes) {
           listener.onMessage(new OkHttpWebSocketImpl(webSocket), bytes.asByteBuffer());
         }
-        
+
         @Override
         public void onMessage(okhttp3.WebSocket webSocket, String text) {
           listener.onMessage(new OkHttpWebSocketImpl(webSocket), text);
         }
-        
+
         @Override
         public void onClosing(okhttp3.WebSocket webSocket, int code, String reason) {
           listener.onClose(new OkHttpWebSocketImpl(webSocket), code, reason);
         }
-        
+
       });
       return future;
     }
@@ -110,17 +111,17 @@ public WebSocket.Builder header(String name, String value) {
       builder = builder.addHeader(name, value);
       return this;
     }
-    
+
     @Override
     public WebSocket.Builder setHeader(String k, String v) {
       builder = builder.header(k, v);
       return this;
     }
-    
+
   }
-  
+
   private okhttp3.WebSocket webSocket;
-  
+
   public OkHttpWebSocketImpl(okhttp3.WebSocket webSocket) {
     this.webSocket = webSocket;
   }
@@ -134,10 +135,10 @@ public boolean send(ByteBuffer buffer) {
   public boolean sendClose(int code, String reason) {
     return webSocket.close(code, reason);
   }
-  
+
   @Override
   public long queueSize() {
     return webSocket.queueSize();
   }
-  
-}
\ No newline at end of file
+
+}