diff --git a/ssl/tls1.h b/ssl/tls1.h
index b32b713..c1b6546 100644
--- a/ssl/tls1.h
+++ b/ssl/tls1.h
@@ -208,6 +208,11 @@
 /* Temporary extension type */
 #define TLSEXT_TYPE_renegotiate                 0xff01
 
+#ifndef OPENSSL_NO_NPN
+/* This is not an IANA defined extension number */
+#define TLSEXT_TYPE_next_proto_neg		13172
+#endif
+
 /* NameType value from RFC 3546 */
 #define TLSEXT_NAMETYPE_host_name 0
 /* status request value from RFC 3546 */