diff --git a/include/binder/Binder.h b/include/binder/Binder.h
index ba3ac4b..16f2c4a 100644
--- a/include/binder/Binder.h
+++ b/include/binder/Binder.h
@@ -17,6 +17,7 @@
 #ifndef ANDROID_BINDER_H
 #define ANDROID_BINDER_H
 
+#include <stdatomic.h>
 #include <binder/IBinder.h>
 
 // ---------------------------------------------------------------------------
@@ -69,7 +70,7 @@
 
     class Extras;
 
-            Extras*     mExtras;
+    atomic_uintptr_t    mExtras;  // should be atomic<Extras *>
             void*       mReserved0;
 };