Index: libcxx/trunk/src/thread.cpp
===================================================================
--- libcxx/trunk/src/thread.cpp
+++ libcxx/trunk/src/thread.cpp
@@ -17,10 +17,10 @@
 #include "limits"
 #include <sys/types.h>
 #if !defined(_WIN32)
-#if !defined(__sun__) && !defined(__linux__) && !defined(_AIX)
-#include <sys/sysctl.h>
-#endif // !__sun__ && !__linux__ && !_AIX
-#include <unistd.h>
+# if !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__)
+#   include <sys/sysctl.h>
+# endif // !defined(__sun__) && !defined(__linux__) && !defined(_AIX) && !defined(__native_client__)
+# include <unistd.h>
 #endif // !_WIN32
 
 #if defined(__NetBSD__)