diff --git a/libcxx/include/__threading_support b/libcxx/include/__threading_support --- a/libcxx/include/__threading_support +++ b/libcxx/include/__threading_support @@ -445,7 +445,7 @@ int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t *__m) { - return mtx_init(__m, mtx_recursive) == thrd_success ? 0 : EINVAL; + return mtx_init(__m, mtx_plain | mtx_recursive) == thrd_success ? 0 : EINVAL; } int __libcpp_recursive_mutex_lock(__libcpp_recursive_mutex_t *__m)