diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index f0b731c..f216aab 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -157,7 +157,7 @@
   uint64_t flags;
 
   /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */
-  void*   reserved_addr;
+  void*   _Nullable reserved_addr;
   /** Used by `ANDROID_DLEXT_RESERVED_ADDRESS` and `ANDROID_DLEXT_RESERVED_ADDRESS_HINT`. */
   size_t  reserved_size;
 
@@ -170,7 +170,7 @@
   off64_t library_fd_offset;
 
   /** Used by `ANDROID_DLEXT_USE_NAMESPACE`. */
-  struct android_namespace_t* library_namespace;
+  struct android_namespace_t* _Nullable library_namespace;
 } android_dlextinfo;
 
 /**
@@ -180,7 +180,7 @@
  *
  * Available since API level 21.
  */
-void* android_dlopen_ext(const char* __filename, int __flags, const android_dlextinfo* __info)
+void* _Nullable android_dlopen_ext(const char* _Nullable __filename, int __flags, const android_dlextinfo* _Nullable __info)
   __INTRODUCED_IN(21);
 
 __END_DECLS