diff --git a/websocket-sharp/Server/WebSocketServiceHost.cs b/websocket-sharp/Server/WebSocketServiceHost.cs
index 276284e0..8ee62e42 100644
--- a/websocket-sharp/Server/WebSocketServiceHost.cs
+++ b/websocket-sharp/Server/WebSocketServiceHost.cs
@@ -155,9 +155,16 @@ namespace WebSocketSharp.Server
     /// <summary>
     /// Gets or sets the wait time for the response to the WebSocket Ping or Close.
     /// </summary>
+    /// <remarks>
+    /// The set operation does nothing if the server has already started or
+    /// it is shutting down.
+    /// </remarks>
     /// <value>
     /// A <see cref="TimeSpan"/> that represents the wait time for the response.
     /// </value>
+    /// <exception cref="ArgumentException">
+    /// The value specified for a set operation is zero or less.
+    /// </exception>
     public TimeSpan WaitTime {
       get {
         return _sessions.WaitTime;