diff --git a/websocket-sharp/Server/WebSocketBehavior.cs b/websocket-sharp/Server/WebSocketBehavior.cs
index 43fe9d29..3019e32c 100644
--- a/websocket-sharp/Server/WebSocketBehavior.cs
+++ b/websocket-sharp/Server/WebSocketBehavior.cs
@@ -384,19 +384,21 @@ namespace WebSocketSharp.Server
     #region Protected Methods
 
     /// <summary>
-    /// Calls the <see cref="OnError"/> method with the specified <paramref name="message"/> and
-    /// <paramref name="exception"/>.
+    /// Calls the <see cref="OnError"/> method with the specified message.
     /// </summary>
-    /// <remarks>
-    /// This method doesn't call the <see cref="OnError"/> method if <paramref name="message"/> is
-    /// <see langword="null"/> or empty.
-    /// </remarks>
     /// <param name="message">
     /// A <see cref="string"/> that represents the error message.
     /// </param>
     /// <param name="exception">
-    /// An <see cref="Exception"/> instance that represents the cause of the error if any.
+    /// An <see cref="Exception"/> instance that represents the cause of
+    /// the error if present.
     /// </param>
+    /// <exception cref="ArgumentNullException">
+    /// <paramref name="message"/> is <see langword="null"/>.
+    /// </exception>
+    /// <exception cref="ArgumentException">
+    /// <paramref name="message"/> is an empty string.
+    /// </exception>
     protected void Error (string message, Exception exception)
     {
       if (message == null)