diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index d4112a9e9..9ddcdb94a 100644
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -299,7 +299,6 @@ POSSIBILITY OF SUCH DAMAGE.
 # if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) \
   && !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
 #  define TORRENT_WINRT
-#  define TORRENT_USE_CRYPTOGRAPHIC_BUFFER 1
 # endif
 #endif
 
@@ -308,7 +307,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_SOLARIS
 #define TORRENT_USE_IFCONF 1
 #define TORRENT_HAS_SALEN 0
-#define TORRENT_HAS_SEM_RELTIMEDWAIT 1
 #define TORRENT_HAVE_MMAP 1
 #define TORRENT_HAS_SYMLINK 1
 
@@ -385,10 +383,6 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_USE_GETIPFORWARDTABLE 0
 #endif
 
-#ifndef TORRENT_HAS_SEM_RELTIMEDWAIT
-#define TORRENT_HAS_SEM_RELTIMEDWAIT 0
-#endif
-
 #ifndef TORRENT_USE_LOCALE
 #define TORRENT_USE_LOCALE 0
 #endif