diff --git a/websocket-sharp/Server/IWebSocketSession.cs b/websocket-sharp/Server/IWebSocketSession.cs
index c323da00..587776dd 100644
--- a/websocket-sharp/Server/IWebSocketSession.cs
+++ b/websocket-sharp/Server/IWebSocketSession.cs
@@ -38,6 +38,19 @@ namespace WebSocketSharp.Server
   {
     #region Properties
 
+    /// <summary>
+    /// Gets the current state of the WebSocket connection for the session.
+    /// </summary>
+    /// <value>
+    ///   <para>
+    ///   One of the <see cref="WebSocketState"/> enum values.
+    ///   </para>
+    ///   <para>
+    ///   It indicates the current state of the connection.
+    ///   </para>
+    /// </value>
+    WebSocketState ConnectionState { get; }
+
     /// <summary>
     /// Gets the information in the WebSocket handshake request.
     /// </summary>
@@ -73,19 +86,6 @@ namespace WebSocketSharp.Server
     /// </value>
     DateTime StartTime { get; }
 
-    /// <summary>
-    /// Gets the current state of the WebSocket connection for the session.
-    /// </summary>
-    /// <value>
-    ///   <para>
-    ///   One of the <see cref="WebSocketState"/> enum values.
-    ///   </para>
-    ///   <para>
-    ///   It indicates the current state of the connection.
-    ///   </para>
-    /// </value>
-    WebSocketState State { get; }
-
     #endregion
   }
 }
diff --git a/websocket-sharp/Server/WebSocketBehavior.cs b/websocket-sharp/Server/WebSocketBehavior.cs
index d75ae616..2d191cb2 100644
--- a/websocket-sharp/Server/WebSocketBehavior.cs
+++ b/websocket-sharp/Server/WebSocketBehavior.cs
@@ -112,6 +112,29 @@ namespace WebSocketSharp.Server
 
     #region Public Properties
 
+    /// <summary>
+    /// Gets the current state of the WebSocket connection for a session.
+    /// </summary>
+    /// <value>
+    ///   <para>
+    ///   One of the <see cref="WebSocketState"/> enum values.
+    ///   </para>
+    ///   <para>
+    ///   It indicates the current state of the connection.
+    ///   </para>
+    ///   <para>
+    ///   <see cref="WebSocketState.Connecting"/> if the session has not
+    ///   started yet.
+    ///   </para>
+    /// </value>
+    public WebSocketState ConnectionState {
+      get {
+        return _websocket != null
+               ? _websocket.ReadyState
+               : WebSocketState.Connecting;
+      }
+    }
+
     /// <summary>
     /// Gets the information in a handshake request to the WebSocket service.
     /// </summary>
@@ -299,7 +322,7 @@ namespace WebSocketSharp.Server
       }
 
       set {
-        if (State != WebSocketState.Connecting) {
+        if (ConnectionState != WebSocketState.Connecting) {
           var msg = "The session has already started.";
           throw new InvalidOperationException (msg);
         }
@@ -334,29 +357,6 @@ namespace WebSocketSharp.Server
       }
     }
 
-    /// <summary>
-    /// Gets the current state of the WebSocket connection for a session.
-    /// </summary>
-    /// <value>
-    ///   <para>
-    ///   One of the <see cref="WebSocketState"/> enum values.
-    ///   </para>
-    ///   <para>
-    ///   It indicates the current state of the connection.
-    ///   </para>
-    ///   <para>
-    ///   <see cref="WebSocketState.Connecting"/> if the session has not
-    ///   started yet.
-    ///   </para>
-    /// </value>
-    public WebSocketState State {
-      get {
-        return _websocket != null
-               ? _websocket.ReadyState
-               : WebSocketState.Connecting;
-      }
-    }
-
     #endregion
 
     #region Private Methods
diff --git a/websocket-sharp/Server/WebSocketSessionManager.cs b/websocket-sharp/Server/WebSocketSessionManager.cs
index 32d59c85..f7144b0c 100644
--- a/websocket-sharp/Server/WebSocketSessionManager.cs
+++ b/websocket-sharp/Server/WebSocketSessionManager.cs
@@ -1639,7 +1639,7 @@ namespace WebSocketSharp.Server
 
           IWebSocketSession session;
           if (_sessions.TryGetValue (id, out session)) {
-            var state = session.State;
+            var state = session.ConnectionState;
             if (state == WebSocketState.Open)
               session.Context.WebSocket.Close (CloseStatusCode.Abnormal);
             else if (state == WebSocketState.Closing)