diff --git a/include/libtorrent/config.hpp b/include/libtorrent/config.hpp
index f9de4457e..6a38bf124 100644
--- a/include/libtorrent/config.hpp
+++ b/include/libtorrent/config.hpp
@@ -203,7 +203,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #define TORRENT_USE_GETADAPTERSADDRESSES 1
 #define TORRENT_HAS_SALEN 0
 #define TORRENT_USE_GETIPFORWARDTABLE 1
+#ifndef TORRENT_USE_UNC_PATHS
 #define TORRENT_USE_UNC_PATHS 1
+#endif
 
 // ==== WINDOWS ===
 #elif defined WIN32
@@ -220,7 +222,9 @@ POSSIBILITY OF SUCH DAMAGE.
 #endif
 #define TORRENT_USE_RLIMIT 0
 #define TORRENT_HAS_FALLOCATE 0
+#ifndef TORRENT_USE_UNC_PATHS
 #define TORRENT_USE_UNC_PATHS 1
+#endif
 
 // ==== SOLARIS ===
 #elif defined sun || defined __sun