diff --git a/src/shrpx_http2_upstream.cc b/src/shrpx_http2_upstream.cc
index 434873ac..470585af 100644
--- a/src/shrpx_http2_upstream.cc
+++ b/src/shrpx_http2_upstream.cc
@@ -1206,11 +1206,12 @@ int Http2Upstream::send_reply(Downstream *downstream, const uint8_t *body,
   }
 
   const auto &resp = downstream->response();
+  auto &httpconf = get_config()->http;
 
   const auto &headers = resp.fs.headers();
   auto nva = std::vector<nghttp2_nv>();
   // 2 for :status and server
-  nva.reserve(2 + headers.size());
+  nva.reserve(2 + headers.size() + httpconf.add_response_headers.size());
 
   std::string status_code_str;
   auto response_status_const = http2::stringify_status(resp.http_status);
@@ -1242,6 +1243,10 @@ int Http2Upstream::send_reply(Downstream *downstream, const uint8_t *body,
         http2::make_nv_ls_nocopy("server", get_config()->http.server_name));
   }
 
+  for (auto &p : httpconf.add_response_headers) {
+    nva.push_back(http2::make_nv_nocopy(p.name, p.value));
+  }
+
   rv = nghttp2_submit_response(session_, downstream->get_stream_id(),
                                nva.data(), nva.size(), data_prd_ptr);
   if (nghttp2_is_fatal(rv)) {
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index cc72e8f5..c807e753 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -798,6 +798,15 @@ int HttpsUpstream::send_reply(Downstream *downstream, const uint8_t *body,
     output->append("\r\n");
   }
 
+  auto &httpconf = get_config()->http;
+
+  for (auto &p : httpconf.add_response_headers) {
+    output->append(p.name);
+    output->append(": ");
+    output->append(p.value);
+    output->append("\r\n");
+  }
+
   output->append("\r\n");
 
   output->append(body, bodylen);
diff --git a/src/shrpx_spdy_upstream.cc b/src/shrpx_spdy_upstream.cc
index a44f2a46..ee80a144 100644
--- a/src/shrpx_spdy_upstream.cc
+++ b/src/shrpx_spdy_upstream.cc
@@ -850,9 +850,12 @@ int SpdyUpstream::send_reply(Downstream *downstream, const uint8_t *body,
 
   const auto &headers = resp.fs.headers();
 
+  auto &httpconf = get_config()->http;
+
   auto nva = std::vector<const char *>();
-  // 3 for :status, :version and server
-  nva.reserve(3 + headers.size());
+  // 6 for :status, :version and server.  1 for last terminal nullptr.
+  nva.reserve(6 + headers.size() * 2 +
+              httpconf.add_response_headers.size() * 2 + 1);
 
   nva.push_back(":status");
   nva.push_back(status_string.c_str());
@@ -879,6 +882,11 @@ int SpdyUpstream::send_reply(Downstream *downstream, const uint8_t *body,
     nva.push_back(get_config()->http.server_name.c_str());
   }
 
+  for (auto &p : httpconf.add_response_headers) {
+    nva.push_back(p.name.c_str());
+    nva.push_back(p.value.c_str());
+  }
+
   nva.push_back(nullptr);
 
   rv = spdylay_submit_response(session_, downstream->get_stream_id(),