diff --git a/src/HtmlParser.cc b/src/HtmlParser.cc
index ea3acc2e..2c4398e4 100644
--- a/src/HtmlParser.cc
+++ b/src/HtmlParser.cc
@@ -80,7 +80,7 @@ void start_element_func
  const xmlChar *name,
  const xmlChar **attrs)
 {
-  auto parser_data = reinterpret_cast<ParserData*>(user_data);
+  auto parser_data = static_cast<ParserData*>(user_data);
   if(util::strieq(reinterpret_cast<const char*>(name), "link")) {
     auto rel_attr = get_attr(attrs, "rel");
     auto href_attr = get_attr(attrs, "href");
diff --git a/src/HttpServer.cc b/src/HttpServer.cc
index 624338af..f5683096 100644
--- a/src/HttpServer.cc
+++ b/src/HttpServer.cc
@@ -216,7 +216,7 @@ namespace {
 void readcb(bufferevent *bev, void *ptr)
 {
   int rv;
-  auto handler = reinterpret_cast<Http2Handler*>(ptr);
+  auto handler = static_cast<Http2Handler*>(ptr);
   rv = handler->on_read();
   if(rv != 0) {
     delete_handler(handler);
@@ -231,7 +231,7 @@ void writecb(bufferevent *bev, void *ptr)
     return;
   }
   int rv;
-  auto handler = reinterpret_cast<Http2Handler*>(ptr);
+  auto handler = static_cast<Http2Handler*>(ptr);
   rv = handler->on_write();
   if(rv != 0) {
     delete_handler(handler);
@@ -242,7 +242,7 @@ void writecb(bufferevent *bev, void *ptr)
 namespace {
 void eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto handler = reinterpret_cast<Http2Handler*>(ptr);
+  auto handler = static_cast<Http2Handler*>(ptr);
   if(events & BEV_EVENT_CONNECTED) {
     // SSL/TLS handshake completed
     if(handler->verify_npn_result() != 0) {
@@ -267,7 +267,7 @@ namespace {
 void connhd_readcb(bufferevent *bev, void *ptr)
 {
   uint8_t data[24];
-  auto handler = reinterpret_cast<Http2Handler*>(ptr);
+  auto handler = static_cast<Http2Handler*>(ptr);
   size_t leftlen = handler->get_left_connhd_len();
   auto input = bufferevent_get_input(bev);
   int readlen = evbuffer_remove(input, data, leftlen);
@@ -353,7 +353,7 @@ int Http2Handler::on_write()
 namespace {
 void settings_timeout_cb(evutil_socket_t fd, short what, void *arg)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(arg);
+  auto hd = static_cast<Http2Handler*>(arg);
   hd->terminate_session(NGHTTP2_SETTINGS_TIMEOUT);
   hd->on_write();
 }
@@ -606,7 +606,7 @@ ssize_t hd_send_callback(nghttp2_session *session,
                          const uint8_t *data, size_t len, int flags,
                          void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   return hd->sendcb(data, len);
 }
 } // namespace
@@ -615,7 +615,7 @@ namespace {
 ssize_t hd_recv_callback(nghttp2_session *session,
                          uint8_t *data, size_t len, int flags, void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   return hd->recvcb(data, len);
 }
 } // namespace
@@ -778,7 +778,7 @@ int on_header_callback(nghttp2_session *session,
                        const uint8_t *value, size_t valuelen,
                        void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(hd->get_config()->verbose) {
     verbose_on_header_callback(session, frame, name, namelen, value, valuelen,
                                user_data);
@@ -812,7 +812,7 @@ int on_end_headers_callback(nghttp2_session *session,
      frame->headers.cat != NGHTTP2_HCAT_REQUEST) {
     return 0;
   }
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   auto stream = hd->get_stream(frame->hd.stream_id);
   if(!stream) {
     return 0;
@@ -847,7 +847,7 @@ namespace {
 int hd_on_frame_recv_callback
 (nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(hd->get_config()->verbose) {
     print_session_id(hd->session_id());
     verbose_on_frame_recv_callback(session, frame, user_data);
@@ -884,7 +884,7 @@ int hd_on_frame_recv_callback
 int htdocs_on_request_recv_callback
 (nghttp2_session *session, int32_t stream_id, void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   auto stream = hd->get_stream(stream_id);
   if(stream) {
     prepare_response(stream, hd);
@@ -896,7 +896,7 @@ namespace {
 int hd_before_frame_send_callback
 (nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(frame->hd.type == NGHTTP2_PUSH_PROMISE) {
     auto stream_id = frame->push_promise.promised_stream_id;
     auto req = util::make_unique<Request>(stream_id);
@@ -914,7 +914,7 @@ int hd_on_frame_send_callback
 (nghttp2_session *session, const nghttp2_frame *frame,
  void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(frame->hd.type == NGHTTP2_PUSH_PROMISE) {
     auto stream = hd->get_stream(frame->push_promise.promised_stream_id);
     if(stream) {
@@ -945,7 +945,7 @@ int hd_on_data_recv_callback
  void *user_data)
 {
   // TODO Handle POST
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(hd->get_config()->verbose) {
     print_session_id(hd->session_id());
     verbose_on_data_recv_callback(session, length, flags, stream_id,
@@ -960,7 +960,7 @@ int hd_on_data_send_callback
 (nghttp2_session *session, uint16_t length,  uint8_t flags, int32_t stream_id,
  void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   if(hd->get_config()->verbose) {
     print_session_id(hd->session_id());
     verbose_on_data_send_callback(session, length, flags, stream_id,
@@ -975,7 +975,7 @@ int on_stream_close_callback
 (nghttp2_session *session, int32_t stream_id, nghttp2_error_code error_code,
  void *user_data)
 {
-  auto hd = reinterpret_cast<Http2Handler*>(user_data);
+  auto hd = static_cast<Http2Handler*>(user_data);
   hd->remove_stream(stream_id);
   if(hd->get_config()->verbose) {
     print_session_id(hd->session_id());
@@ -1061,8 +1061,7 @@ namespace {
 int next_proto_cb(SSL *s, const unsigned char **data, unsigned int *len,
                   void *arg)
 {
-  auto next_proto =
-    reinterpret_cast<std::pair<unsigned char*, size_t>* >(arg);
+  auto next_proto = static_cast<std::pair<unsigned char*, size_t>* >(arg);
   *data = next_proto->first;
   *len = next_proto->second;
   return SSL_TLSEXT_ERR_OK;
@@ -1082,7 +1081,7 @@ namespace {
 void evlistener_acceptcb(evconnlistener *listener, int fd,
                          sockaddr *addr, int addrlen, void *arg)
 {
-  auto handler = reinterpret_cast<ListenEventHandler*>(arg);
+  auto handler = static_cast<ListenEventHandler*>(arg);
   handler->accept_connection(fd, addr, addrlen);
 }
 } // namespace
@@ -1170,7 +1169,7 @@ int alpn_select_proto_cb(SSL* ssl,
                          const unsigned char *in, unsigned int inlen,
                          void *arg)
 {
-  auto config = reinterpret_cast<HttpServer*>(arg)->get_config();
+  auto config = static_cast<HttpServer*>(arg)->get_config();
   if(config->verbose) {
     std::cout << "[ALPN] client offers:" << std::endl;
   }
diff --git a/src/nghttp.cc b/src/nghttp.cc
index cc8e9b04..bee490c1 100644
--- a/src/nghttp.cc
+++ b/src/nghttp.cc
@@ -888,7 +888,7 @@ int htp_msg_begincb(http_parser *htp)
 namespace {
 int htp_status_completecb(http_parser *htp)
 {
-  auto client = reinterpret_cast<HttpClient*>(htp->data);
+  auto client = static_cast<HttpClient*>(htp->data);
   client->upgrade_response_status_code = htp->status_code;
   return 0;
 }
@@ -897,7 +897,7 @@ int htp_status_completecb(http_parser *htp)
 namespace {
 int htp_msg_completecb(http_parser *htp)
 {
-  auto client = reinterpret_cast<HttpClient*>(htp->data);
+  auto client = static_cast<HttpClient*>(htp->data);
   client->upgrade_response_complete = true;
   return 0;
 }
@@ -1026,7 +1026,7 @@ void update_html_parser(HttpClient *client, Request *req,
 namespace {
 HttpClient* get_session(void *user_data)
 {
-  return reinterpret_cast<HttpClient*>(user_data);
+  return static_cast<HttpClient*>(user_data);
 }
 } // namespace
 
@@ -1302,7 +1302,7 @@ namespace {
 void upgrade_readcb(bufferevent *bev, void *ptr)
 {
   int rv;
-  auto client = reinterpret_cast<HttpClient*>(ptr);
+  auto client = static_cast<HttpClient*>(ptr);
   rv = client->on_upgrade_read();
   if(rv != 0) {
     client->disconnect();
@@ -1314,7 +1314,7 @@ namespace {
 void readcb(bufferevent *bev, void *ptr)
 {
   int rv;
-  auto client = reinterpret_cast<HttpClient*>(ptr);
+  auto client = static_cast<HttpClient*>(ptr);
   rv = client->on_read();
   if(rv != 0) {
     client->disconnect();
@@ -1329,7 +1329,7 @@ void writecb(bufferevent *bev, void *ptr)
     return;
   }
   int rv;
-  auto client = reinterpret_cast<HttpClient*>(ptr);
+  auto client = static_cast<HttpClient*>(ptr);
   rv = client->on_write();
   if(rv != 0) {
     client->disconnect();
@@ -1341,7 +1341,7 @@ namespace {
 void eventcb(bufferevent *bev, short events, void *ptr)
 {
   int rv;
-  auto client = reinterpret_cast<HttpClient*>(ptr);
+  auto client = static_cast<HttpClient*>(ptr);
   if(events & BEV_EVENT_CONNECTED) {
     client->state = STATE_CONNECTED;
     int fd = bufferevent_getfd(bev);
@@ -1420,7 +1420,7 @@ ssize_t client_send_callback(nghttp2_session *session,
                              const uint8_t *data, size_t len, int flags,
                              void *user_data)
 {
-  auto client = reinterpret_cast<HttpClient*>(user_data);
+  auto client = static_cast<HttpClient*>(user_data);
   return client->sendcb(data, len);
 }
 } // namespace
@@ -1430,7 +1430,7 @@ ssize_t client_recv_callback(nghttp2_session *session,
                              uint8_t *buf, size_t len, int flags,
                              void *user_data)
 {
-  auto client = reinterpret_cast<HttpClient*>(user_data);
+  auto client = static_cast<HttpClient*>(user_data);
   return client->recvcb(buf, len);
 }
 } // namespace
diff --git a/src/shrpx.cc b/src/shrpx.cc
index 7394936b..cb069604 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -62,7 +62,7 @@ namespace {
 void ssl_acceptcb(evconnlistener *listener, int fd,
                   sockaddr *addr, int addrlen, void *arg)
 {
-  auto handler = reinterpret_cast<ListenHandler*>(arg);
+  auto handler = static_cast<ListenHandler*>(arg);
   handler->accept_connection(fd, addr, addrlen);
 }
 } // namespace
diff --git a/src/shrpx_client_handler.cc b/src/shrpx_client_handler.cc
index 4966726f..4ce0ef9f 100644
--- a/src/shrpx_client_handler.cc
+++ b/src/shrpx_client_handler.cc
@@ -47,7 +47,7 @@ namespace shrpx {
 namespace {
 void upstream_readcb(bufferevent *bev, void *arg)
 {
-  auto handler = reinterpret_cast<ClientHandler*>(arg);
+  auto handler = static_cast<ClientHandler*>(arg);
   int rv = handler->on_read();
   if(rv != 0) {
     delete handler;
@@ -58,7 +58,7 @@ void upstream_readcb(bufferevent *bev, void *arg)
 namespace {
 void upstream_writecb(bufferevent *bev, void *arg)
 {
-  auto handler = reinterpret_cast<ClientHandler*>(arg);
+  auto handler = static_cast<ClientHandler*>(arg);
   // We actually depend on write low-warter mark == 0.
   if(handler->get_outbuf_length() > 0) {
     // Possibly because of deferred callback, we may get this callback
@@ -80,7 +80,7 @@ void upstream_writecb(bufferevent *bev, void *arg)
 namespace {
 void upstream_eventcb(bufferevent *bev, short events, void *arg)
 {
-  auto handler = reinterpret_cast<ClientHandler*>(arg);
+  auto handler = static_cast<ClientHandler*>(arg);
   bool finish = false;
   if(events & BEV_EVENT_EOF) {
     if(LOG_ENABLED(INFO)) {
@@ -136,7 +136,7 @@ void upstream_http2_connhd_readcb(bufferevent *bev, void *arg)
 {
   // This callback assumes upstream is Http2Upstream.
   uint8_t data[NGHTTP2_CLIENT_CONNECTION_HEADER_LEN];
-  auto handler = reinterpret_cast<ClientHandler*>(arg);
+  auto handler = static_cast<ClientHandler*>(arg);
   auto leftlen = handler->get_left_connhd_len();
   auto input = bufferevent_get_input(bev);
   auto readlen = evbuffer_remove(input, data, leftlen);
@@ -173,7 +173,7 @@ void upstream_http1_connhd_readcb(bufferevent *bev, void *arg)
 {
   // This callback assumes upstream is HttpsUpstream.
   uint8_t data[NGHTTP2_CLIENT_CONNECTION_HEADER_LEN];
-  auto handler = reinterpret_cast<ClientHandler*>(arg);
+  auto handler = static_cast<ClientHandler*>(arg);
   auto leftlen = handler->get_left_connhd_len();
   auto input = bufferevent_get_input(bev);
   auto readlen = evbuffer_copyout(input, data, leftlen);
diff --git a/src/shrpx_http2_downstream_connection.cc b/src/shrpx_http2_downstream_connection.cc
index 2700938f..23a715ae 100644
--- a/src/shrpx_http2_downstream_connection.cc
+++ b/src/shrpx_http2_downstream_connection.cc
@@ -158,12 +158,12 @@ ssize_t http2_data_read_callback(nghttp2_session *session,
                                  nghttp2_data_source *source,
                                  void *user_data)
 {
-  auto sd = reinterpret_cast<StreamData*>
+  auto sd = static_cast<StreamData*>
     (nghttp2_session_get_stream_user_data(session, stream_id));
   if(!sd || !sd->dconn) {
     return NGHTTP2_ERR_DEFERRED;
   }
-  auto dconn = reinterpret_cast<Http2DownstreamConnection*>(source->ptr);
+  auto dconn = static_cast<Http2DownstreamConnection*>(source->ptr);
   auto downstream = dconn->get_downstream();
   if(!downstream) {
     // In this case, RST_STREAM should have been issued. But depending
diff --git a/src/shrpx_http2_session.cc b/src/shrpx_http2_session.cc
index 2b973ec3..deea214e 100644
--- a/src/shrpx_http2_session.cc
+++ b/src/shrpx_http2_session.cc
@@ -148,7 +148,7 @@ namespace {
 void notify_readcb(bufferevent *bev, void *arg)
 {
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(arg);
+  auto http2session = static_cast<Http2Session*>(arg);
   http2session->clear_notify();
   switch(http2session->get_state()) {
   case Http2Session::DISCONNECTED:
@@ -172,7 +172,7 @@ void notify_readcb(bufferevent *bev, void *arg)
 namespace {
 void notify_eventcb(bufferevent *bev, short events, void *arg)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(arg);
+  auto http2session = static_cast<Http2Session*>(arg);
   // TODO should DIE()?
   if(events & BEV_EVENT_EOF) {
     SSLOG(ERROR, http2session) << "Notification connection lost: EOF";
@@ -222,7 +222,7 @@ namespace {
 void readcb(bufferevent *bev, void *ptr)
 {
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(ptr);
+  auto http2session = static_cast<Http2Session*>(ptr);
   rv = http2session->on_read();
   if(rv != 0) {
     http2session->disconnect();
@@ -237,7 +237,7 @@ void writecb(bufferevent *bev, void *ptr)
     return;
   }
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(ptr);
+  auto http2session = static_cast<Http2Session*>(ptr);
   rv = http2session->on_write();
   if(rv != 0) {
     http2session->disconnect();
@@ -248,7 +248,7 @@ void writecb(bufferevent *bev, void *ptr)
 namespace {
 void eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(ptr);
+  auto http2session = static_cast<Http2Session*>(ptr);
   if(events & BEV_EVENT_CONNECTED) {
     if(LOG_ENABLED(INFO)) {
       SSLOG(INFO, http2session) << "Connection established";
@@ -288,7 +288,7 @@ void eventcb(bufferevent *bev, short events, void *ptr)
 namespace {
 void proxy_readcb(bufferevent *bev, void *ptr)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(ptr);
+  auto http2session = static_cast<Http2Session*>(ptr);
   if(http2session->on_read_proxy() == 0) {
     switch(http2session->get_state()) {
     case Http2Session::PROXY_CONNECTED:
@@ -313,7 +313,7 @@ void proxy_readcb(bufferevent *bev, void *ptr)
 namespace {
 void proxy_eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(ptr);
+  auto http2session = static_cast<Http2Session*>(ptr);
   if(events & BEV_EVENT_CONNECTED) {
     if(LOG_ENABLED(INFO)) {
       SSLOG(INFO, http2session) << "Connected to the proxy";
@@ -498,7 +498,7 @@ void Http2Session::unwrap_free_bev()
 namespace {
 int htp_hdrs_completecb(http_parser *htp)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(htp->data);
+  auto http2session = static_cast<Http2Session*>(htp->data);
   // We just check status code here
   if(htp->status_code == 200) {
     if(LOG_ENABLED(INFO)) {
@@ -693,7 +693,7 @@ ssize_t send_callback(nghttp2_session *session,
                       void *user_data)
 {
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   auto bev = http2session->get_bev();
   auto output = bufferevent_get_output(bev);
   // Check buffer length and return WOULDBLOCK if it is large enough.
@@ -717,12 +717,12 @@ int on_stream_close_callback
  void *user_data)
 {
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   if(LOG_ENABLED(INFO)) {
     SSLOG(INFO, http2session) << "Stream stream_id=" << stream_id
                               << " is being closed";
   }
-  auto sd = reinterpret_cast<StreamData*>
+  auto sd = static_cast<StreamData*>
     (nghttp2_session_get_stream_user_data(session, stream_id));
   if(sd == 0) {
     // We might get this close callback when pushed streams are
@@ -756,7 +756,7 @@ int on_stream_close_callback
 namespace {
 void settings_timeout_cb(evutil_socket_t fd, short what, void *arg)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(arg);
+  auto http2session = static_cast<Http2Session*>(arg);
   SSLOG(INFO, http2session) << "SETTINGS timeout";
   if(http2session->terminate_session(NGHTTP2_SETTINGS_TIMEOUT) != 0) {
     http2session->disconnect();
@@ -808,7 +808,7 @@ int on_header_callback(nghttp2_session *session,
      frame->headers.cat != NGHTTP2_HCAT_RESPONSE) {
     return 0;
   }
-  auto sd = reinterpret_cast<StreamData*>
+  auto sd = static_cast<StreamData*>
     (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
   if(!sd || !sd->dconn) {
     return 0;
@@ -839,8 +839,8 @@ int on_end_headers_callback(nghttp2_session *session,
     return 0;
   }
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
-  auto sd = reinterpret_cast<StreamData*>
+  auto http2session = static_cast<Http2Session*>(user_data);
+  auto sd = static_cast<StreamData*>
     (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
   if(!sd || !sd->dconn) {
     return 0;
@@ -943,7 +943,7 @@ namespace {
 int on_frame_recv_callback
 (nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   switch(frame->hd.type) {
   case NGHTTP2_HEADERS: {
     if(frame->headers.cat == NGHTTP2_HCAT_REQUEST) {
@@ -955,7 +955,7 @@ int on_frame_recv_callback
     if(frame->headers.cat != NGHTTP2_HCAT_RESPONSE) {
       break;
     }
-    auto sd = reinterpret_cast<StreamData*>
+    auto sd = static_cast<StreamData*>
       (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
     if(!sd || !sd->dconn) {
       http2session->submit_rst_stream(frame->hd.stream_id,
@@ -972,7 +972,7 @@ int on_frame_recv_callback
     break;
   }
   case NGHTTP2_RST_STREAM: {
-    auto sd = reinterpret_cast<StreamData*>
+    auto sd = static_cast<StreamData*>
       (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
     if(sd && sd->dconn) {
       auto downstream = sd->dconn->get_downstream();
@@ -1032,8 +1032,8 @@ int on_data_chunk_recv_callback(nghttp2_session *session,
                                 void *user_data)
 {
   int rv;
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
-  auto sd = reinterpret_cast<StreamData*>
+  auto http2session = static_cast<Http2Session*>(user_data);
+  auto sd = static_cast<StreamData*>
     (nghttp2_session_get_stream_user_data(session, stream_id));
   if(!sd || !sd->dconn) {
     http2session->submit_rst_stream(stream_id, NGHTTP2_INTERNAL_ERROR);
@@ -1061,10 +1061,10 @@ int before_frame_send_callback(nghttp2_session *session,
                                const nghttp2_frame *frame,
                                void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   if(frame->hd.type == NGHTTP2_HEADERS &&
      frame->headers.cat == NGHTTP2_HCAT_REQUEST) {
-    auto sd = reinterpret_cast<StreamData*>
+    auto sd = static_cast<StreamData*>
       (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
     if(!sd || !sd->dconn) {
       http2session->submit_rst_stream(frame->hd.stream_id, NGHTTP2_CANCEL);
@@ -1085,7 +1085,7 @@ namespace {
 int on_frame_send_callback(nghttp2_session* session,
                            const nghttp2_frame *frame, void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   if(frame->hd.type == NGHTTP2_SETTINGS &&
      (frame->hd.flags & NGHTTP2_FLAG_ACK) == 0) {
     if(http2session->start_settings_timer() != 0) {
@@ -1101,7 +1101,7 @@ int on_frame_not_send_callback(nghttp2_session *session,
                                const nghttp2_frame *frame,
                                int lib_error_code, void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   SSLOG(WARNING, http2session) << "Failed to send control frame type="
                                << frame->hd.type << ", "
                                << "lib_error_code=" << lib_error_code << ":"
@@ -1110,7 +1110,7 @@ int on_frame_not_send_callback(nghttp2_session *session,
      frame->headers.cat == NGHTTP2_HCAT_REQUEST) {
     // To avoid stream hanging around, flag Downstream::MSG_RESET and
     // terminate the upstream and downstream connections.
-    auto sd = reinterpret_cast<StreamData*>
+    auto sd = static_cast<StreamData*>
       (nghttp2_session_get_stream_user_data(session, frame->hd.stream_id));
     if(!sd) {
       return 0;
@@ -1138,7 +1138,7 @@ int on_frame_recv_parse_error_callback(nghttp2_session *session,
                                        size_t payloadlen, int lib_error_code,
                                        void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   if(LOG_ENABLED(INFO)) {
     SSLOG(INFO, http2session)
       << "Failed to parse received control frame. type="
@@ -1156,7 +1156,7 @@ int on_unknown_frame_recv_callback(nghttp2_session *session,
                                    const uint8_t *payload, size_t payloadlen,
                                    void *user_data)
 {
-  auto http2session = reinterpret_cast<Http2Session*>(user_data);
+  auto http2session = static_cast<Http2Session*>(user_data);
   if(LOG_ENABLED(INFO)) {
     SSLOG(INFO, http2session) << "Received unknown control frame";
   }
diff --git a/src/shrpx_http2_upstream.cc b/src/shrpx_http2_upstream.cc
index 54a26be8..fd464ba8 100644
--- a/src/shrpx_http2_upstream.cc
+++ b/src/shrpx_http2_upstream.cc
@@ -54,7 +54,7 @@ ssize_t send_callback(nghttp2_session *session,
                       void *user_data)
 {
   int rv;
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   auto handler = upstream->get_client_handler();
   auto bev = handler->get_bev();
   auto output = bufferevent_get_output(bev);
@@ -78,7 +78,7 @@ int on_stream_close_callback
 (nghttp2_session *session, int32_t stream_id, nghttp2_error_code error_code,
  void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Stream stream_id=" << stream_id
                          << " is being closed";
@@ -156,7 +156,7 @@ int Http2Upstream::upgrade_upstream(HttpsUpstream *http)
 namespace {
 void settings_timeout_cb(evutil_socket_t fd, short what, void *arg)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(arg);
+  auto upstream = static_cast<Http2Upstream*>(arg);
   ULOG(INFO, upstream) << "SETTINGS timeout";
   if(upstream->terminate_session(NGHTTP2_SETTINGS_TIMEOUT) != 0) {
     delete upstream->get_client_handler();
@@ -209,7 +209,7 @@ int on_header_callback(nghttp2_session *session,
      frame->headers.cat != NGHTTP2_HCAT_REQUEST) {
     return 0;
   }
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   auto downstream = upstream->find_downstream(frame->hd.stream_id);
   if(!downstream) {
     return 0;
@@ -236,7 +236,7 @@ int on_end_headers_callback(nghttp2_session *session,
     return 0;
   }
   int rv;
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   auto downstream = upstream->find_downstream(frame->hd.stream_id);
   if(!downstream) {
     return 0;
@@ -337,7 +337,7 @@ int on_frame_recv_callback
 (nghttp2_session *session, const nghttp2_frame *frame, void *user_data)
 {
   int rv;
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   switch(frame->hd.type) {
   case NGHTTP2_HEADERS: {
     if(frame->headers.cat != NGHTTP2_HCAT_REQUEST) {
@@ -392,7 +392,7 @@ int on_data_chunk_recv_callback(nghttp2_session *session,
                                 const uint8_t *data, size_t len,
                                 void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   auto downstream = upstream->find_downstream(stream_id);
   if(downstream) {
     if(downstream->push_upload_data_chunk(data, len) != 0) {
@@ -409,7 +409,7 @@ int on_data_recv_callback(nghttp2_session *session,
                           uint16_t length, uint8_t flags, int32_t stream_id,
                           void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   auto downstream = upstream->find_downstream(stream_id);
   if(downstream && (flags & NGHTTP2_FLAG_END_STREAM)) {
     downstream->end_upload_data();
@@ -423,7 +423,7 @@ namespace {
 int on_frame_send_callback(nghttp2_session* session,
                            const nghttp2_frame *frame, void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   if(frame->hd.type == NGHTTP2_SETTINGS &&
      (frame->hd.flags & NGHTTP2_FLAG_ACK) == 0) {
     if(upstream->start_settings_timer() != 0) {
@@ -439,7 +439,7 @@ int on_frame_not_send_callback(nghttp2_session *session,
                                const nghttp2_frame *frame,
                                int lib_error_code, void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   ULOG(WARNING, upstream) << "Failed to send control frame type="
                           << static_cast<uint32_t>(frame->hd.type)
                           << ", lib_error_code=" << lib_error_code << ":"
@@ -464,7 +464,7 @@ int on_frame_recv_parse_error_callback(nghttp2_session *session,
                                        size_t payloadlen, int lib_error_code,
                                        void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Failed to parse received control frame. type="
                          << type
@@ -481,7 +481,7 @@ int on_unknown_frame_recv_callback(nghttp2_session *session,
                                    const uint8_t *payload, size_t payloadlen,
                                    void *user_data)
 {
-  auto upstream = reinterpret_cast<Http2Upstream*>(user_data);
+  auto upstream = static_cast<Http2Upstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Received unknown control frame.";
   }
@@ -642,7 +642,7 @@ ClientHandler* Http2Upstream::get_client_handler() const
 namespace {
 void downstream_readcb(bufferevent *bev, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<Http2Upstream*>(downstream->get_upstream());
   if(downstream->get_request_state() == Downstream::STREAM_CLOSED) {
@@ -701,7 +701,7 @@ void downstream_writecb(bufferevent *bev, void *ptr)
   if(evbuffer_get_length(bufferevent_get_output(bev)) > 0) {
     return;
   }
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<Http2Upstream*>(downstream->get_upstream());
   upstream->resume_read(SHRPX_NO_BUFFER, downstream);
@@ -711,7 +711,7 @@ void downstream_writecb(bufferevent *bev, void *ptr)
 namespace {
 void downstream_eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<Http2Upstream*>(downstream->get_upstream());
   if(events & BEV_EVENT_CONNECTED) {
@@ -879,8 +879,8 @@ ssize_t downstream_data_read_callback(nghttp2_session *session,
                                       nghttp2_data_source *source,
                                       void *user_data)
 {
-  auto downstream = reinterpret_cast<Downstream*>(source->ptr);
-  auto upstream = reinterpret_cast<Http2Upstream*>(downstream->get_upstream());
+  auto downstream = static_cast<Downstream*>(source->ptr);
+  auto upstream = static_cast<Http2Upstream*>(downstream->get_upstream());
   auto handler = upstream->get_client_handler();
   auto body = downstream->get_response_body_buf();
   assert(body);
diff --git a/src/shrpx_http_downstream_connection.cc b/src/shrpx_http_downstream_connection.cc
index 8ce1ff62..b4fb33b3 100644
--- a/src/shrpx_http_downstream_connection.cc
+++ b/src/shrpx_http_downstream_connection.cc
@@ -305,7 +305,7 @@ namespace {
 // Gets called when DownstreamConnection is pooled in ClientHandler.
 void idle_eventcb(bufferevent *bev, short events, void *arg)
 {
-  auto dconn = reinterpret_cast<HttpDownstreamConnection*>(arg);
+  auto dconn = static_cast<HttpDownstreamConnection*>(arg);
   if(events & BEV_EVENT_CONNECTED) {
     // Downstream was detached before connection established?
     // This may be safe to be left.
@@ -381,7 +381,7 @@ bool HttpDownstreamConnection::get_output_buffer_full()
 namespace {
 int htp_hdrs_completecb(http_parser *htp)
 {
-  auto downstream = reinterpret_cast<Downstream*>(htp->data);
+  auto downstream = static_cast<Downstream*>(htp->data);
   downstream->set_response_http_status(htp->status_code);
   downstream->set_response_major(htp->http_major);
   downstream->set_response_minor(htp->http_minor);
@@ -425,7 +425,7 @@ int htp_hdrs_completecb(http_parser *htp)
 namespace {
 int htp_hdr_keycb(http_parser *htp, const char *data, size_t len)
 {
-  auto downstream = reinterpret_cast<Downstream*>(htp->data);
+  auto downstream = static_cast<Downstream*>(htp->data);
   if(downstream->get_response_header_key_prev()) {
     downstream->append_last_response_header_key(data, len);
   } else {
@@ -438,7 +438,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len)
 namespace {
 int htp_hdr_valcb(http_parser *htp, const char *data, size_t len)
 {
-  auto downstream = reinterpret_cast<Downstream*>(htp->data);
+  auto downstream = static_cast<Downstream*>(htp->data);
   if(downstream->get_response_header_key_prev()) {
     downstream->set_last_response_header_value(std::string(data, len));
   } else {
@@ -451,7 +451,7 @@ int htp_hdr_valcb(http_parser *htp, const char *data, size_t len)
 namespace {
 int htp_bodycb(http_parser *htp, const char *data, size_t len)
 {
-  auto downstream = reinterpret_cast<Downstream*>(htp->data);
+  auto downstream = static_cast<Downstream*>(htp->data);
   return downstream->get_upstream()->on_downstream_body
     (downstream, reinterpret_cast<const uint8_t*>(data), len);
 }
@@ -460,7 +460,7 @@ int htp_bodycb(http_parser *htp, const char *data, size_t len)
 namespace {
 int htp_msg_completecb(http_parser *htp)
 {
-  auto downstream = reinterpret_cast<Downstream*>(htp->data);
+  auto downstream = static_cast<Downstream*>(htp->data);
   downstream->set_response_state(Downstream::MSG_COMPLETE);
   // Block reading another response message from (broken?)
   // server. This callback is not called if the connection is
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index ad2d678b..6cdcbacb 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -71,7 +71,7 @@ void HttpsUpstream::reset_current_header_length()
 namespace {
 int htp_msg_begin(http_parser *htp)
 {
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "HTTP request started";
   }
@@ -85,7 +85,7 @@ int htp_msg_begin(http_parser *htp)
 namespace {
 int htp_uricb(http_parser *htp, const char *data, size_t len)
 {
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   auto downstream = upstream->get_downstream();
   downstream->append_request_path(data, len);
   return 0;
@@ -95,7 +95,7 @@ int htp_uricb(http_parser *htp, const char *data, size_t len)
 namespace {
 int htp_hdr_keycb(http_parser *htp, const char *data, size_t len)
 {
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   auto downstream = upstream->get_downstream();
   if(downstream->get_request_header_key_prev()) {
     downstream->append_last_request_header_key(data, len);
@@ -109,7 +109,7 @@ int htp_hdr_keycb(http_parser *htp, const char *data, size_t len)
 namespace {
 int htp_hdr_valcb(http_parser *htp, const char *data, size_t len)
 {
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   auto downstream = upstream->get_downstream();
   if(downstream->get_request_header_key_prev()) {
     downstream->set_last_request_header_value(std::string(data, len));
@@ -124,7 +124,7 @@ namespace {
 int htp_hdrs_completecb(http_parser *htp)
 {
   int rv;
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "HTTP request headers completed";
   }
@@ -199,7 +199,7 @@ namespace {
 int htp_bodycb(http_parser *htp, const char *data, size_t len)
 {
   int rv;
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   auto downstream = upstream->get_downstream();
   rv = downstream->push_upload_data_chunk
     (reinterpret_cast<const uint8_t*>(data), len);
@@ -214,7 +214,7 @@ namespace {
 int htp_msg_completecb(http_parser *htp)
 {
   int rv;
-  auto upstream = reinterpret_cast<HttpsUpstream*>(htp->data);
+  auto upstream = static_cast<HttpsUpstream*>(htp->data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "HTTP request completed";
   }
@@ -393,7 +393,7 @@ int HttpsUpstream::resume_read(IOCtrlReason reason, Downstream *downstream)
 namespace {
 void https_downstream_readcb(bufferevent *bev, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<HttpsUpstream*>(downstream->get_upstream());
   int rv;
@@ -481,7 +481,7 @@ void https_downstream_writecb(bufferevent *bev, void *ptr)
   if(evbuffer_get_length(bufferevent_get_output(bev)) > 0) {
     return;
   }
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<HttpsUpstream*>(downstream->get_upstream());
   // May return -1
@@ -492,7 +492,7 @@ void https_downstream_writecb(bufferevent *bev, void *ptr)
 namespace {
 void https_downstream_eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<HttpsUpstream*>(downstream->get_upstream());
   if(events & BEV_EVENT_CONNECTED) {
diff --git a/src/shrpx_spdy_upstream.cc b/src/shrpx_spdy_upstream.cc
index 903f13c8..ee683ef7 100644
--- a/src/shrpx_spdy_upstream.cc
+++ b/src/shrpx_spdy_upstream.cc
@@ -54,7 +54,7 @@ ssize_t send_callback(spdylay_session *session,
                       void *user_data)
 {
   int rv;
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   auto handler = upstream->get_client_handler();
   auto bev = handler->get_bev();
   auto output = bufferevent_get_output(bev);
@@ -77,7 +77,7 @@ namespace {
 ssize_t recv_callback(spdylay_session *session,
                       uint8_t *data, size_t len, int flags, void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   auto handler = upstream->get_client_handler();
   auto bev = handler->get_bev();
   auto input = bufferevent_get_input(bev);
@@ -97,7 +97,7 @@ void on_stream_close_callback
 (spdylay_session *session, int32_t stream_id, spdylay_status_code status_code,
  void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Stream stream_id=" << stream_id
                          << " is being closed";
@@ -142,7 +142,7 @@ void on_ctrl_recv_callback
 (spdylay_session *session, spdylay_frame_type type, spdylay_frame *frame,
  void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   switch(type) {
   case SPDYLAY_SYN_STREAM: {
     if(LOG_ENABLED(INFO)) {
@@ -243,7 +243,7 @@ void on_data_chunk_recv_callback(spdylay_session *session,
                                  const uint8_t *data, size_t len,
                                  void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   auto downstream = upstream->find_downstream(stream_id);
   if(downstream) {
     if(downstream->push_upload_data_chunk(data, len) != 0) {
@@ -290,7 +290,7 @@ namespace {
 void on_data_recv_callback(spdylay_session *session, uint8_t flags,
                            int32_t stream_id, int32_t length, void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   auto downstream = upstream->find_downstream(stream_id);
   if(downstream && (flags & SPDYLAY_DATA_FLAG_FIN)) {
     downstream->end_upload_data();
@@ -305,7 +305,7 @@ void on_ctrl_not_send_callback(spdylay_session *session,
                                spdylay_frame *frame,
                                int error_code, void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   ULOG(WARNING, upstream) << "Failed to send control frame type=" << type
                           << ", error_code=" << error_code << ":"
                           << spdylay_strerror(error_code);
@@ -328,7 +328,7 @@ void on_ctrl_recv_parse_error_callback(spdylay_session *session,
                                        size_t payloadlen, int error_code,
                                        void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Failed to parse received control frame. type="
                          << type
@@ -344,7 +344,7 @@ void on_unknown_ctrl_recv_callback(spdylay_session *session,
                                    const uint8_t *payload, size_t payloadlen,
                                    void *user_data)
 {
-  auto upstream = reinterpret_cast<SpdyUpstream*>(user_data);
+  auto upstream = static_cast<SpdyUpstream*>(user_data);
   if(LOG_ENABLED(INFO)) {
     ULOG(INFO, upstream) << "Received unknown control frame.";
   }
@@ -500,7 +500,7 @@ ClientHandler* SpdyUpstream::get_client_handler() const
 namespace {
 void spdy_downstream_readcb(bufferevent *bev, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<SpdyUpstream*>(downstream->get_upstream());
   if(downstream->get_request_state() == Downstream::STREAM_CLOSED) {
@@ -559,7 +559,7 @@ void spdy_downstream_writecb(bufferevent *bev, void *ptr)
   if(evbuffer_get_length(bufferevent_get_output(bev)) > 0) {
     return;
   }
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<SpdyUpstream*>(downstream->get_upstream());
   upstream->resume_read(SHRPX_NO_BUFFER, downstream);
@@ -569,7 +569,7 @@ void spdy_downstream_writecb(bufferevent *bev, void *ptr)
 namespace {
 void spdy_downstream_eventcb(bufferevent *bev, short events, void *ptr)
 {
-  auto dconn = reinterpret_cast<DownstreamConnection*>(ptr);
+  auto dconn = static_cast<DownstreamConnection*>(ptr);
   auto downstream = dconn->get_downstream();
   auto upstream = static_cast<SpdyUpstream*>(downstream->get_upstream());
   if(events & BEV_EVENT_CONNECTED) {
@@ -723,8 +723,8 @@ ssize_t spdy_data_read_callback(spdylay_session *session,
                                 spdylay_data_source *source,
                                 void *user_data)
 {
-  auto downstream = reinterpret_cast<Downstream*>(source->ptr);
-  auto upstream = reinterpret_cast<SpdyUpstream*>(downstream->get_upstream());
+  auto downstream = static_cast<Downstream*>(source->ptr);
+  auto upstream = static_cast<SpdyUpstream*>(downstream->get_upstream());
   auto handler = upstream->get_client_handler();
   auto body = downstream->get_response_body_buf();
   assert(body);
diff --git a/src/shrpx_ssl.cc b/src/shrpx_ssl.cc
index 6cd5cbbe..9294c190 100644
--- a/src/shrpx_ssl.cc
+++ b/src/shrpx_ssl.cc
@@ -62,8 +62,7 @@ namespace {
 int next_proto_cb(SSL *s, const unsigned char **data, unsigned int *len,
                   void *arg)
 {
-  auto next_proto =
-    reinterpret_cast<std::pair<unsigned char*, size_t>*>(arg);
+  auto next_proto = static_cast<std::pair<unsigned char*, size_t>*>(arg);
   *data = next_proto->first;
   *len = next_proto->second;
   return SSL_TLSEXT_ERR_OK;
@@ -103,7 +102,7 @@ size_t set_npn_prefs(unsigned char *out, char **protos, size_t len)
 namespace {
 int ssl_pem_passwd_cb(char *buf, int size, int rwflag, void *user_data)
 {
-  auto config = reinterpret_cast<Config*>(user_data);
+  auto config = static_cast<Config*>(user_data);
   int len = (int)strlen(config->private_key_passwd);
   if (size < len + 1) {
     LOG(ERROR) << "ssl_pem_passwd_cb: buf is too small " << size;
@@ -579,8 +578,8 @@ void get_altnames(X509 *cert,
                   std::vector<std::string>& ip_addrs,
                   std::string& common_name)
 {
-  GENERAL_NAMES* altnames;
-  altnames = reinterpret_cast<GENERAL_NAMES*>
+  GENERAL_NAMES *altnames =
+    static_cast<GENERAL_NAMES*>
     (X509_get_ext_d2i(cert, NID_subject_alt_name, nullptr, nullptr));
   if(altnames) {
     util::auto_delete<GENERAL_NAMES*> altnames_deleter(altnames,
diff --git a/src/shrpx_worker.cc b/src/shrpx_worker.cc
index 1e0099da..acac1240 100644
--- a/src/shrpx_worker.cc
+++ b/src/shrpx_worker.cc
@@ -57,7 +57,7 @@ Worker::~Worker()
 namespace {
 void readcb(bufferevent *bev, void *arg)
 {
-  auto receiver = reinterpret_cast<ThreadEventReceiver*>(arg);
+  auto receiver = static_cast<ThreadEventReceiver*>(arg);
   receiver->on_read(bev);
 }
 } // namespace