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 516cc070c8..09265a42d2 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
@@ -210,6 +210,7 @@ private void generateGroupClassHeader(
             indent + INDENT + INDENT + "_index = -1;\n" +
             indent + INDENT + INDENT + "_count = count;\n" +
             indent + INDENT + INDENT + "_blockLength = %3$d;\n" +
+            indent + INDENT + INDENT + "_actingVersion = SchemaVersion;\n" +
             indent + INDENT + INDENT + "parentMessage.Limit = parentMessage.Limit + SbeHeaderSize;\n" +
             indent + INDENT + "}\n",
             parentMessageClassName,