Index: include/__threading_support
===================================================================
--- include/__threading_support
+++ include/__threading_support
@@ -376,7 +376,8 @@
 }
 
 // Thread local storage
-int __libcpp_tls_create(__libcpp_tls_key *__key, void (*__at_exit)(void *))
+int __libcpp_tls_create(__libcpp_tls_key *__key,
+                        void (_LIBCPP_TLS_DESTRUCTOR_CC* __at_exit)(void *))
 {
   return pthread_key_create(__key, __at_exit);
 }