diff --git a/src/Runner.Common/Util/VarUtil.cs b/src/Runner.Common/Util/VarUtil.cs
index 81b8ecb23..fba6b1846 100644
--- a/src/Runner.Common/Util/VarUtil.cs
+++ b/src/Runner.Common/Util/VarUtil.cs
@@ -54,6 +54,8 @@ namespace GitHub.Runner.Common.Util
                         return "X64";
                     case Constants.Architecture.Arm:
                         return "ARM";
+                    case Constants.Architecture.Arm64:
+                        return "ARM64";    
                     default:
                         throw new NotSupportedException(); // Should never reach here.
                 }