diff --git a/libc/include/android/dlext.h b/libc/include/android/dlext.h
index f0b731c77..f216aabd4 100644
--- a/libc/include/android/dlext.h
+++ b/libc/include/android/dlext.h
@@ -157,7 +157,7 @@ typedef struct {
   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 @@ typedef struct {
   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 @@ typedef struct {
  *
  * 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
diff --git a/libc/include/android/fdsan.h b/libc/include/android/fdsan.h
index 59ce13330..3de064914 100644
--- a/libc/include/android/fdsan.h
+++ b/libc/include/android/fdsan.h
@@ -159,7 +159,7 @@ uint64_t android_fdsan_get_owner_tag(int fd) __INTRODUCED_IN(29);
  *
  * The return value points to memory with static lifetime, do not attempt to modify it.
  */
-const char* android_fdsan_get_tag_type(uint64_t tag) __INTRODUCED_IN(29);
+const char* _Nonnull android_fdsan_get_tag_type(uint64_t tag) __INTRODUCED_IN(29);
 
 /*
  * Get an owner tag's value, with the type masked off.
diff --git a/libc/include/android/legacy_stdlib_inlines.h b/libc/include/android/legacy_stdlib_inlines.h
index e9b606a04..f0985fe61 100644
--- a/libc/include/android/legacy_stdlib_inlines.h
+++ b/libc/include/android/legacy_stdlib_inlines.h
@@ -38,15 +38,15 @@
 
 __BEGIN_DECLS
 
-static __inline double strtod_l(const char* __s, char** __end_ptr, locale_t __l) {
+static __inline double strtod_l(const char* _Nonnull __s, char* _Nullable * _Nullable __end_ptr, locale_t _Nonnull __l) {
   return strtod(__s, __end_ptr);
 }
 
-static __inline float strtof_l(const char* __s, char** __end_ptr, locale_t __l) {
+static __inline float strtof_l(const char* _Nonnull __s, char* _Nullable * _Nullable __end_ptr, locale_t _Nonnull __l) {
   return strtof(__s, __end_ptr);
 }
 
-static __inline long strtol_l(const char* __s, char** __end_ptr, int __base, locale_t __l) {
+static __inline long strtol_l(const char* _Nonnull __s, char* _Nullable * _Nullable __end_ptr, int __base, locale_t _Nonnull __l) {
   return strtol(__s, __end_ptr, __base);
 }
 
diff --git a/libc/include/android/set_abort_message.h b/libc/include/android/set_abort_message.h
index 5d8d8eeed..2be01a9c6 100644
--- a/libc/include/android/set_abort_message.h
+++ b/libc/include/android/set_abort_message.h
@@ -46,6 +46,6 @@ __BEGIN_DECLS
  *
  * Available since API level 21.
  */
-void android_set_abort_message(const char* __msg) __INTRODUCED_IN(21);
+void android_set_abort_message(const char* _Nullable __msg) __INTRODUCED_IN(21);
 
 __END_DECLS