Index: include/__mutex_base
===================================================================
--- include/__mutex_base
+++ include/__mutex_base
@@ -14,7 +14,9 @@
 #include <__config>
 #include <chrono>
 #include <system_error>
+#ifndef _LIBCPP_HAS_NO_THREADS
 #include <pthread.h>
+#endif
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
Index: include/mutex
===================================================================
--- include/mutex
+++ include/mutex
@@ -178,7 +178,9 @@
 #ifndef _LIBCPP_HAS_NO_VARIADICS
 #include <tuple>
 #endif
+#ifndef _LIBCPP_HAS_NO_THREADS
 #include <sched.h>
+#endif
 
 #include <__undef_min_max>