diff --git a/libutils/include/utils/Flattenable.h b/libutils/include/utils/Flattenable.h
index 9d00602..953b859 100644
--- a/libutils/include/utils/Flattenable.h
+++ b/libutils/include/utils/Flattenable.h
@@ -17,6 +17,9 @@
 #ifndef ANDROID_UTILS_FLATTENABLE_H
 #define ANDROID_UTILS_FLATTENABLE_H
 
+// DO NOT USE: please use parcelable instead
+// This code is deprecated and will not be supported via AIDL code gen. For data
+// to be sent over binder, please use parcelables.
 
 #include <stdint.h>
 #include <string.h>
@@ -28,7 +31,9 @@
 
 namespace android {
 
-
+// DO NOT USE: please use parcelable instead
+// This code is deprecated and will not be supported via AIDL code gen. For data
+// to be sent over binder, please use parcelables.
 class FlattenableUtils {
 public:
     template<size_t N>
@@ -79,7 +84,9 @@
     }
 };
 
-
+// DO NOT USE: please use parcelable instead
+// This code is deprecated and will not be supported via AIDL code gen. For data
+// to be sent over binder, please use parcelables.
 /*
  * The Flattenable protocol allows an object to serialize itself out
  * to a byte-buffer and an array of file descriptors.
@@ -131,6 +138,9 @@
     return static_cast<T*>(this)->T::unflatten(buffer, size, fds, count);
 }
 
+// DO NOT USE: please use parcelable instead
+// This code is deprecated and will not be supported via AIDL code gen. For data
+// to be sent over binder, please use parcelables.
 /*
  * LightFlattenable is a protocol allowing object to serialize themselves out
  * to a byte-buffer. Because it doesn't handle file-descriptors,
@@ -171,6 +181,9 @@
     return static_cast<T*>(this)->T::unflatten(buffer, size);
 }
 
+// DO NOT USE: please use parcelable instead
+// This code is deprecated and will not be supported via AIDL code gen. For data
+// to be sent over binder, please use parcelables.
 /*
  * LightFlattenablePod is an implementation of the LightFlattenable protocol
  * for POD (plain-old-data) objects.