diff --git a/src/include/Tls.h b/src/include/Tls.h
index 5b56306..fff6e0a 100644
--- a/src/include/Tls.h
+++ b/src/include/Tls.h
@@ -26,6 +26,8 @@
 
 #include <Stream.h>
 
+#define TLS_LIBRESSL 2
+
 extern Stream *
  TlsClientStream(int, const char *);