diff --git a/BotSharp.MachineLearning/CRFLite/Decoder/DecoderOptions.cs b/BotSharp.MachineLearning/CRFLite/Decoder/DecoderOptions.cs
index 86e7ff77..0bc034d9 100644
--- a/BotSharp.MachineLearning/CRFLite/Decoder/DecoderOptions.cs
+++ b/BotSharp.MachineLearning/CRFLite/Decoder/DecoderOptions.cs
@@ -11,13 +11,11 @@ namespace BotSharp.MachineLearning.CRFLite.Decoder
         /// <summary>
         /// 
         /// </summary>
-        [Required]
         public string ModelFileName;
 
         /// <summary>
         /// 
         /// </summary>
-        [Required]
         public string InputFileName;
 
         /// <summary>
diff --git a/BotSharp.MachineLearning/CRFLite/Encoder/EncoderOptions.cs b/BotSharp.MachineLearning/CRFLite/Encoder/EncoderOptions.cs
index d7c5d3e0..35ae1fb6 100644
--- a/BotSharp.MachineLearning/CRFLite/Encoder/EncoderOptions.cs
+++ b/BotSharp.MachineLearning/CRFLite/Encoder/EncoderOptions.cs
@@ -40,19 +40,16 @@ namespace BotSharp.MachineLearning.CRFLite.Encoder
         /// <summary>
         /// Template file name
         /// </summary>
-        [Required]
         public string TemplateFileName { get; set; }
 
         /// <summary>
         /// Training corpus file name
         /// </summary>
-        [Required]
         public string TrainingCorpusFileName { get; set; }
 
         /// <summary>
         /// Encoded model file name
         /// </summary>
-        [Required]
         public string ModelFileName { get; set; }
 
         /// <summary>