diff --git a/XmlSchemaClassGenerator.Console/Program.cs b/XmlSchemaClassGenerator.Console/Program.cs
index b0dafb2..05f4241 100644
--- a/XmlSchemaClassGenerator.Console/Program.cs
+++ b/XmlSchemaClassGenerator.Console/Program.cs
@@ -17,7 +17,7 @@ namespace XmlSchemaClassGenerator.Console
 {
     static class Program
     {
-        static void Main(string[] args)
+        static int Main(string[] args)
         {
             var showHelp = args.Length == 0;
             var namespaces = new List<string>();
@@ -165,7 +165,7 @@ A file name may be given by appending a pipe sign (|) followed by a file name (l
             if (showHelp)
             {
                 ShowHelp(options);
-                return;
+                return 0;
             }
 
             var uris = new List<string>();
@@ -181,7 +181,7 @@ A file name may be given by appending a pipe sign (|) followed by a file name (l
                 if (expandedGlob.Count == 0)
                 {
                     System.Console.WriteLine($"No files found for '{globOrUri}'");
-                    Environment.Exit(1);
+                    Environment.Exit((int)ExitCodes.FileNotFound);
                 }
 
                 uris.AddRange(expandedGlob);
@@ -267,6 +267,17 @@ A file name may be given by appending a pipe sign (|) followed by a file name (l
             if (verbose) { generator.Log = s => System.Console.Out.WriteLine(s); }
 
             generator.Generate(uris);
+
+            return !generator.ValidationError ? (int)ExitCodes.Ok : (int)ExitCodes.ValidationError;
+        }
+
+        enum ExitCodes
+        {
+            Ok = 0,
+            FileNotFound = 1,
+            InvalidNameSubstitutionFile = 2,
+            InvalidNamespaceFile = 3,
+            ValidationError = 4
         }
 
         private static void ParseNamespaceFiles(List<string> namespaces, List<string> namespaceFiles)
@@ -280,12 +291,12 @@ private static void ParseNamespaceFiles(List<string> namespaces, List<string> na
                     var parts = line.Split('=');
 
                     if (parts.Length == 1)
-                        parts = new[] { string.Empty, parts[0] };
+                        parts = [string.Empty, parts[0]];
 
                     if (parts.Length != 2)
                     {
                         System.Console.WriteLine($"{namespaceFile}:{number}: Line format is XML namespace = C# namespace [file name]");
-                        Environment.Exit(1);
+                        Environment.Exit((int)ExitCodes.InvalidNamespaceFile);
                     }
 
                     var xmlns = parts[0].Trim();
@@ -312,7 +323,7 @@ private static void ParseNameSubstituteFiles(List<string> nameSubstitutes, List<
                     if (parts.Length != 2)
                     {
                         System.Console.WriteLine($"{nameSubstituteFile}:{number}: Line format is prefixed type/member name = substitute name");
-                        Environment.Exit(2);
+                        Environment.Exit((int)ExitCodes.InvalidNameSubstitutionFile);
                     }
 
                     var generatedName = parts[0].Trim();
diff --git a/XmlSchemaClassGenerator/FileOutputWriter.cs b/XmlSchemaClassGenerator/FileOutputWriter.cs
index 2d15524..fc50c6c 100644
--- a/XmlSchemaClassGenerator/FileOutputWriter.cs
+++ b/XmlSchemaClassGenerator/FileOutputWriter.cs
@@ -61,8 +61,7 @@ protected virtual void WriteFile(string path, CodeCompileUnit cu)
             }
             finally
             {
-                if (fs != null)
-                    fs.Dispose();
+                fs?.Dispose();
             }
         }
 
diff --git a/XmlSchemaClassGenerator/Generator.cs b/XmlSchemaClassGenerator/Generator.cs
index b9e7b69..6f3ce81 100644
--- a/XmlSchemaClassGenerator/Generator.cs
+++ b/XmlSchemaClassGenerator/Generator.cs
@@ -336,6 +336,8 @@ public bool SeparateNamespaceHierarchy
             set { _configuration.SeparateNamespaceHierarchy = value; }
         }
 
+        public bool ValidationError { get; private set; }
+
         static Generator()
         {
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
@@ -347,12 +349,15 @@ public void Generate(IEnumerable<string> files)
             var settings = new XmlReaderSettings { DtdProcessing = DtdProcessing.Ignore };
             var readers = files.Select(f => XmlReader.Create(f, settings));
 
+            ValidationError = false;
+
             set.XmlResolver = new XmlUrlResolver();
             set.ValidationEventHandler += (s, e) =>
             {
                 var ex = e.Exception as Exception;
                 while (ex != null)
                 {
+                    ValidationError = true;
                     Log?.Invoke(ex.Message);
                     ex = ex.InnerException;
                 }
diff --git a/XmlSchemaClassGenerator/TypeModel.cs b/XmlSchemaClassGenerator/TypeModel.cs
index ec66cf2..f5923a7 100644
--- a/XmlSchemaClassGenerator/TypeModel.cs
+++ b/XmlSchemaClassGenerator/TypeModel.cs
@@ -1094,7 +1094,7 @@ private IEnumerable<CodeAttributeDeclaration> GetAttributes(bool isArray, TypeMo
                         var qualifiedName = xmlSchemaType.GetQualifiedName();
 
                         if ((qualifiedName.Namespace == XmlSchema.Namespace && qualifiedName.Name != "anySimpleType") &&
-                            (xmlSchemaType.Datatype.ValueType == typeof(DateTime) && configuration.DateTimeWithTimeZone) == false)
+                            (xmlSchemaType.Datatype.ValueType == typeof(DateTime) && Configuration.DateTimeWithTimeZone) == false)
                         {
                             args.Add(new("DataType", new CodePrimitiveExpression(qualifiedName.Name)));
                             break;