diff --git a/README.rst b/README.rst
index cfc21b6e..07db75fe 100644
--- a/README.rst
+++ b/README.rst
@@ -4,6 +4,19 @@ nghttp2 - HTTP/2.0 C Library
 This is an experimental implementation of Hypertext Transfer Protocol
 version 2.0.
 
+This branch explores upcoming HPACK changes:
+
+* Unified request/response static header table
+* Insert index 0 and remove the last one
+* Drop substitution
+* Huffman encoding
+
+With these changes, the implemented protocol is not compatible with
+HTTP-draft-06/2.0. Therefore, this branch uses
+HTTP-nghttp2hpack-06/2.0 as protocol identifier. The following section
+does not reflect this protocl identifier change. Read it by replacing
+HTTP-draft-06/2.0 with HTTP-nghttp2hpack-06/2.0.
+
 Development Status
 ------------------
 
diff --git a/lib/includes/nghttp2/nghttp2.h b/lib/includes/nghttp2/nghttp2.h
index ead216c6..58b8fd11 100644
--- a/lib/includes/nghttp2/nghttp2.h
+++ b/lib/includes/nghttp2/nghttp2.h
@@ -40,13 +40,13 @@ extern "C" {
  *
  * The protocol version identification of this library supports.
  */
-#define NGHTTP2_PROTO_VERSION_ID "HTTP-draft-06/2.0"
+#define NGHTTP2_PROTO_VERSION_ID "HTTP-nghttp2hpack-06/2.0"
 /**
  * @macro
  *
  * The length of :macro:`NGHTTP2_PROTO_VERSION_ID`.
  */
-#define NGHTTP2_PROTO_VERSION_ID_LEN 17
+#define NGHTTP2_PROTO_VERSION_ID_LEN 24
 
 struct nghttp2_session;
 /**
diff --git a/src/HttpServer.cc b/src/HttpServer.cc
index 24193327..a704460d 100644
--- a/src/HttpServer.cc
+++ b/src/HttpServer.cc
@@ -1018,11 +1018,11 @@ int HttpServer::run()
                          verify_callback);
     }
 
-    proto_list[0] = 17;
+    proto_list[0] = NGHTTP2_PROTO_VERSION_ID_LEN;
     memcpy(&proto_list[1], NGHTTP2_PROTO_VERSION_ID,
            NGHTTP2_PROTO_VERSION_ID_LEN);
     next_proto.first = proto_list;
-    next_proto.second = 18;
+    next_proto.second = proto_list[0] + 1;
 
     SSL_CTX_set_next_protos_advertised_cb(ssl_ctx, next_proto_cb, &next_proto);
   }
diff --git a/tests/nghttp2_npn_test.c b/tests/nghttp2_npn_test.c
index f0c9842b..f97b59f2 100644
--- a/tests/nghttp2_npn_test.c
+++ b/tests/nghttp2_npn_test.c
@@ -32,15 +32,15 @@ static void http2(void)
 {
   const unsigned char p[] = {
     8, 'h', 't', 't', 'p', '/', '1', '.', '1',
-    17, 'H', 'T', 'T', 'P', '-', 'd', 'r', 'a', 'f', 't', '-', '0', '6', '/',
+    24, 'H', 'T', 'T', 'P', '-', 'n', 'g', 'h', 't', 't', 'p', '2', 'h', 'p', 'a', 'c', 'k', '-', '0', '6', '/',
     '2', '.', '0',
     6, 's', 'p', 'd', 'y', '/', '3'
   };
   unsigned char outlen;
   unsigned char* out;
   CU_ASSERT(1 == nghttp2_select_next_protocol(&out, &outlen, p, sizeof(p)));
-  CU_ASSERT(17 == outlen);
-  CU_ASSERT(memcmp("HTTP-draft-06/2.0", out, outlen) == 0);
+  CU_ASSERT(24 == outlen);
+  CU_ASSERT(memcmp(NGHTTP2_PROTO_VERSION_ID, out, outlen) == 0);
 }
 
 static void http11(void)