diff --git a/src/shrpx.cc b/src/shrpx.cc
index d934acd2..b1979d2d 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -335,7 +335,7 @@ void reopen_log_signal_cb(evutil_socket_t sig, short events, void *arg)
   auto listener_handler = static_cast<ListenHandler*>(arg);
 
   if(LOG_ENABLED(INFO)) {
-    LOG(INFO) << "Reopening log files: worker_info(" << &worker_config << ")";
+    LOG(INFO) << "Reopening log files: worker_info(" << worker_config << ")";
   }
 
   (void)reopen_log_files();
@@ -456,7 +456,7 @@ void graceful_shutdown_signal_cb(evutil_socket_t sig, short events, void *arg)
 
   listener_handler->accept_pending_connection();
 
-  worker_config.graceful_shutdown = true;
+  worker_config->graceful_shutdown = true;
 
   listener_handler->graceful_shutdown_worker();
 }
@@ -495,7 +495,7 @@ void refresh_cb(evutil_socket_t sig, short events, void *arg)
   // In multi threaded mode (get_config()->num_worker > 1), we have to
   // wait for event notification to workers to finish.
   if(get_config()->num_worker == 1 &&
-     worker_config.graceful_shutdown &&
+     worker_config->graceful_shutdown &&
      (!worker_stat || worker_stat->num_connections == 0)) {
     event_base_loopbreak(listener_handler->get_evbase());
   }
@@ -1642,15 +1642,15 @@ int main(int argc, char **argv)
   }
 
   if(get_config()->uid != 0) {
-    if(worker_config.accesslog_fd != -1 &&
-       fchown(worker_config.accesslog_fd,
+    if(worker_config->accesslog_fd != -1 &&
+       fchown(worker_config->accesslog_fd,
               get_config()->uid, get_config()->gid)  == -1) {
       auto error = errno;
       LOG(WARNING) << "Changing owner of access log file failed: "
                    << strerror(error);
     }
-    if(worker_config.errorlog_fd != -1 &&
-       fchown(worker_config.errorlog_fd,
+    if(worker_config->errorlog_fd != -1 &&
+       fchown(worker_config->errorlog_fd,
               get_config()->uid, get_config()->gid) == -1) {
       auto error = errno;
       LOG(WARNING) << "Changing owner of error log file failed: "
diff --git a/src/shrpx_client_handler.cc b/src/shrpx_client_handler.cc
index e5989fe2..363bf1ed 100644
--- a/src/shrpx_client_handler.cc
+++ b/src/shrpx_client_handler.cc
@@ -274,7 +274,7 @@ ClientHandler::~ClientHandler()
 
   // TODO If backend is http/2, and it is in CONNECTED state, signal
   // it and make it loopbreak when output is zero.
-  if(worker_config.graceful_shutdown && worker_stat_->num_connections == 0) {
+  if(worker_config->graceful_shutdown && worker_stat_->num_connections == 0) {
     event_base_loopbreak(get_evbase());
   }
 
diff --git a/src/shrpx_http_downstream_connection.cc b/src/shrpx_http_downstream_connection.cc
index d79185de..829a44d9 100644
--- a/src/shrpx_http_downstream_connection.cc
+++ b/src/shrpx_http_downstream_connection.cc
@@ -255,7 +255,7 @@ int HttpDownstreamConnection::push_request_headers()
   if(LOG_ENABLED(INFO)) {
     const char *hdrp;
     std::string nhdrs;
-    if(worker_config.errorlog_tty) {
+    if(worker_config->errorlog_tty) {
       nhdrs = http::colorizeHeaders(hdrs.c_str());
       hdrp = nhdrs.c_str();
     } else {
diff --git a/src/shrpx_https_upstream.cc b/src/shrpx_https_upstream.cc
index 61696f76..ef867eee 100644
--- a/src/shrpx_https_upstream.cc
+++ b/src/shrpx_https_upstream.cc
@@ -940,7 +940,7 @@ void HttpsUpstream::log_response_headers(const std::string& hdrs) const
 {
   const char *hdrp;
   std::string nhdrs;
-  if(worker_config.errorlog_tty) {
+  if(worker_config->errorlog_tty) {
     nhdrs = http::colorizeHeaders(hdrs.c_str());
     hdrp = nhdrs.c_str();
   } else {
diff --git a/src/shrpx_listen_handler.cc b/src/shrpx_listen_handler.cc
index b19a479f..99fdc180 100644
--- a/src/shrpx_listen_handler.cc
+++ b/src/shrpx_listen_handler.cc
@@ -82,7 +82,7 @@ void worker_writecb(bufferevent *bev, void *ptr)
   auto listener_handler = static_cast<ListenHandler*>(ptr);
   auto output = bufferevent_get_output(bev);
 
-  if(!worker_config.graceful_shutdown ||
+  if(!worker_config->graceful_shutdown ||
      evbuffer_get_length(output) != 0) {
     return;
   }
diff --git a/src/shrpx_log.cc b/src/shrpx_log.cc
index 62db35b6..37f16962 100644
--- a/src/shrpx_log.cc
+++ b/src/shrpx_log.cc
@@ -102,8 +102,10 @@ Log::~Log()
 {
   int rv;
 
+  auto wconf = worker_config;
+
   if(!log_enabled(severity_) ||
-     (worker_config.errorlog_fd == -1 && !get_config()->errorlog_syslog)) {
+     (wconf->errorlog_fd == -1 && !get_config()->errorlog_syslog)) {
     return;
   }
 
@@ -116,7 +118,7 @@ Log::~Log()
   }
 
   char buf[4096];
-  auto tty = worker_config.errorlog_tty;
+  auto tty = wconf->errorlog_tty;
 
   auto cached_time = get_config()->cached_time;
 
@@ -138,13 +140,15 @@ Log::~Log()
 
   auto nwrite = std::min(static_cast<size_t>(rv), sizeof(buf) - 1);
 
-  while(write(worker_config.errorlog_fd, buf, nwrite) == -1 && errno == EINTR);
+  while(write(wconf->errorlog_fd, buf, nwrite) == -1 && errno == EINTR);
 }
 
 void upstream_accesslog(const std::string& client_ip, unsigned int status_code,
                         Downstream *downstream)
 {
-  if(worker_config.accesslog_fd == -1 && !get_config()->accesslog_syslog) {
+  auto wconf = worker_config;
+
+  if(wconf->accesslog_fd == -1 && !get_config()->accesslog_syslog) {
     return;
   }
 
@@ -209,25 +213,26 @@ void upstream_accesslog(const std::string& client_ip, unsigned int status_code,
     return;
   }
 
-  while(write(worker_config.accesslog_fd, buf, nwrite) == -1 &&
-        errno == EINTR);
+  while(write(wconf->accesslog_fd, buf, nwrite) == -1 && errno == EINTR);
 }
 
 int reopen_log_files()
 {
   int res = 0;
 
-  if(worker_config.accesslog_fd != -1) {
-    close(worker_config.accesslog_fd);
-    worker_config.accesslog_fd = -1;
+  auto wconf = worker_config;
+
+  if(wconf->accesslog_fd != -1) {
+    close(wconf->accesslog_fd);
+    wconf->accesslog_fd = -1;
   }
 
   if(!get_config()->accesslog_syslog && get_config()->accesslog_file) {
 
-    worker_config.accesslog_fd =
+    wconf->accesslog_fd =
       util::reopen_log_file(get_config()->accesslog_file.get());
 
-    if(worker_config.accesslog_fd == -1) {
+    if(wconf->accesslog_fd == -1) {
       LOG(ERROR) << "Failed to open accesslog file "
                  << get_config()->accesslog_file.get();
       res = -1;
@@ -241,7 +246,7 @@ int reopen_log_files()
     new_errorlog_fd = util::reopen_log_file(get_config()->errorlog_file.get());
 
     if(new_errorlog_fd == -1) {
-      if(worker_config.errorlog_fd != -1) {
+      if(wconf->errorlog_fd != -1) {
         LOG(ERROR) << "Failed to open errorlog file "
                    << get_config()->errorlog_file.get();
       } else {
@@ -254,15 +259,15 @@ int reopen_log_files()
     }
   }
 
-  if(worker_config.errorlog_fd != -1) {
-    close(worker_config.errorlog_fd);
-    worker_config.errorlog_fd = -1;
-    worker_config.errorlog_tty = false;
+  if(wconf->errorlog_fd != -1) {
+    close(wconf->errorlog_fd);
+    wconf->errorlog_fd = -1;
+    wconf->errorlog_tty = false;
   }
 
   if(new_errorlog_fd != -1) {
-    worker_config.errorlog_fd = new_errorlog_fd;
-    worker_config.errorlog_tty = isatty(worker_config.errorlog_fd);
+    wconf->errorlog_fd = new_errorlog_fd;
+    wconf->errorlog_tty = isatty(wconf->errorlog_fd);
   }
 
   return res;
diff --git a/src/shrpx_log.h b/src/shrpx_log.h
index ddf5dc1f..d060d79b 100644
--- a/src/shrpx_log.h
+++ b/src/shrpx_log.h
@@ -97,8 +97,8 @@ private:
   static int severity_thres_;
 };
 
-#define TTY_HTTP_HD (worker_config.errorlog_tty ? "\033[1;34m" : "")
-#define TTY_RST (worker_config.errorlog_tty ? "\033[0m" : "")
+#define TTY_HTTP_HD (worker_config->errorlog_tty ? "\033[1;34m" : "")
+#define TTY_RST (worker_config->errorlog_tty ? "\033[0m" : "")
 
 void upstream_accesslog(const std::string& client_ip, unsigned int status_code,
                         Downstream *downstream);
diff --git a/src/shrpx_thread_event_receiver.cc b/src/shrpx_thread_event_receiver.cc
index b1587c9e..ab7e9ed2 100644
--- a/src/shrpx_thread_event_receiver.cc
+++ b/src/shrpx_thread_event_receiver.cc
@@ -73,7 +73,7 @@ void ThreadEventReceiver::on_read(bufferevent *bev)
     if(wev.type == REOPEN_LOG) {
       if(LOG_ENABLED(INFO)) {
         LOG(INFO) << "Reopening log files: worker_info("
-                  << &worker_config << ")";
+                  << worker_config << ")";
       }
 
       reopen_log_files();
@@ -86,7 +86,7 @@ void ThreadEventReceiver::on_read(bufferevent *bev)
         LOG(INFO) << "Graceful shutdown commencing";
       }
 
-      worker_config.graceful_shutdown = true;
+      worker_config->graceful_shutdown = true;
 
       if(worker_stat_->num_connections == 0) {
         event_base_loopbreak(evbase_);
diff --git a/src/shrpx_worker_config.cc b/src/shrpx_worker_config.cc
index 866b5158..5fd5a421 100644
--- a/src/shrpx_worker_config.cc
+++ b/src/shrpx_worker_config.cc
@@ -36,7 +36,7 @@ WorkerConfig::WorkerConfig()
 #ifndef NOTHREADS
 thread_local
 #endif // NOTHREADS
-WorkerConfig worker_config;
+WorkerConfig *worker_config = new WorkerConfig();
 
 } // namespace shrpx
 
diff --git a/src/shrpx_worker_config.h b/src/shrpx_worker_config.h
index 9a2643bd..2527dbed 100644
--- a/src/shrpx_worker_config.h
+++ b/src/shrpx_worker_config.h
@@ -44,7 +44,7 @@ extern
 #ifndef NOTHREADS
 thread_local
 #endif // NOTHREADS
-WorkerConfig worker_config;
+WorkerConfig *worker_config;
 
 } // namespace shrpx