diff --git a/README.rst b/README.rst
index 39d3a519eff232341bbfbb14f93aecc474d5b8b8..7be33e862d183489e756425fc02c9c37969f469a 100644
--- a/README.rst
+++ b/README.rst
@@ -47,12 +47,15 @@ branch) as crypto backend:
 
 * OpenSSL (https://github.com/openssl/openssl/)
 
+At the moment, the patched OpenSSL is required to compile ngtcp2 to
+enable 0-RTT.  See below.
+
 Build from git
 --------------
 
 .. code-block:: text
 
-   $ git clone --depth 1 https://github.com/openssl/openssl
+   $ git clone --depth 1 -b quic https://github.com/tatsuhiro-t/openssl
    $ cd openssl
    $ # For Linux
    $ ./config enable-tls1_3 --prefix=$PWD/build
diff --git a/ci/build_openssl.sh b/ci/build_openssl.sh
index edcde43fb1d2c3d5ff56184795bf7fcb9e869b90..fecb329644e8f8e449ccab6a8cfce40d087ebdf0 100755
--- a/ci/build_openssl.sh
+++ b/ci/build_openssl.sh
@@ -2,7 +2,7 @@
 #build last openssl master (for Travis)
 
 cd ..
-git clone --depth 1 https://github.com/openssl/openssl
+git clone --depth 1 -b quic https://github.com/tatsuhiro-t/openssl
 cd openssl
 ./config enable-tls1_3 --prefix=$PWD/build
 make -j$(nproc)