Index: llvm-toolchain-snapshot_9~svn353038/libcxx/src/thread.cpp
===================================================================
--- llvm-toolchain-snapshot_9~svn353038.orig/libcxx/src/thread.cpp
+++ llvm-toolchain-snapshot_9~svn353038/libcxx/src/thread.cpp
@@ -18,7 +18,7 @@
 
 #if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
 # include <sys/param.h>
-# if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__)
+# if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__) || defined(__FreeBSD_kernel__)
 #   include <sys/sysctl.h>
 # endif
 #endif // defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))