diff --git a/extension/apple/ExecuTorch/Exported/ExecuTorchLog.h b/extension/apple/ExecuTorch/Exported/ExecuTorchLog.h
index a71591c7ba7..17d9f339618 100644
--- a/extension/apple/ExecuTorch/Exported/ExecuTorchLog.h
+++ b/extension/apple/ExecuTorch/Exported/ExecuTorchLog.h
@@ -49,6 +49,7 @@ NS_SWIFT_NAME(LogSink)
  * A singleton class for managing log sinks and dispatching log messages.
  */
 NS_SWIFT_NAME(Log)
+__attribute__((objc_subclassing_restricted))
 @interface ExecuTorchLog : NSObject
 
 /// The shared singleton log instance.
diff --git a/extension/apple/ExecuTorch/Exported/ExecuTorchModule.h b/extension/apple/ExecuTorch/Exported/ExecuTorchModule.h
index 9cc1b71249d..cda9a914bc3 100644
--- a/extension/apple/ExecuTorch/Exported/ExecuTorchModule.h
+++ b/extension/apple/ExecuTorch/Exported/ExecuTorchModule.h
@@ -16,6 +16,7 @@ NS_ASSUME_NONNULL_BEGIN
  * and its debug name.
  */
 NS_SWIFT_NAME(TensorMetadata)
+__attribute__((objc_subclassing_restricted))
 @interface ExecuTorchTensorMetadata : NSObject
 
 /** The size of each dimension. */
@@ -46,6 +47,7 @@ NS_SWIFT_NAME(TensorMetadata)
  * per-tensor metadata, buffer sizes, backends, and instruction count.
  */
 NS_SWIFT_NAME(MethodMetadata)
+__attribute__((objc_subclassing_restricted))
 @interface ExecuTorchMethodMetadata : NSObject
 
 /** The method’s name. */