diff --git a/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java b/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java
index e3671c14c0..1a45d845c0 100644
--- a/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java
+++ b/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpGenerator.java
@@ -614,7 +614,9 @@ private CharSequence generateFileHeader(final String packageName)
         }
 
         return String.format(
-            "/* Generated SBE (Simple Binary Encoding) message codec */\n\n" +
+            "// <auto-generated>\n" +
+            "//     Generated SBE (Simple Binary Encoding) message codec\n" +
+            "// </auto-generated>\n\n" +
             "#pragma warning disable 1591 // disable warning on missing comments\n" +
             "using System;\n" +
             "using Org.SbeTool.Sbe.Dll;\n\n" +
diff --git a/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpNamespaceOutputManager.java b/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpNamespaceOutputManager.java
index 389d942fc4..b3d7c20c26 100644
--- a/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpNamespaceOutputManager.java
+++ b/sbe-tool/src/main/java/uk/co/real_logic/sbe/generation/csharp/CSharpNamespaceOutputManager.java
@@ -71,7 +71,7 @@ public CSharpNamespaceOutputManager(final String baseDirName, final String packa
      */
     public Writer createOutput(final String name) throws IOException
     {
-        final File targetFile = new File(outputDir, name + ".cs");
+        final File targetFile = new File(outputDir, name + ".g.cs");
         return Files.newBufferedWriter(targetFile.toPath(), StandardCharsets.UTF_8);
     }
 }