diff --git a/src/shrpx.cc b/src/shrpx.cc
index ece98e36..cd36a1cf 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -1272,8 +1272,6 @@ constexpr auto DEFAULT_ACCESSLOG_FORMAT = StringRef::from_lit(
 
 namespace {
 void fill_default_config(Config *config) {
-  *config = {};
-
   config->num_worker = 1;
   config->conf_path = "/etc/nghttpx/nghttpx.conf";
   config->pid = getpid();
diff --git a/src/shrpx_config.h b/src/shrpx_config.h
index d0645ff3..5ad6585a 100644
--- a/src/shrpx_config.h
+++ b/src/shrpx_config.h
@@ -706,8 +706,14 @@ struct APIConfig {
 };
 
 struct Config {
+  Config() = default;
   ~Config();
 
+  Config(Config &&) = delete;
+  Config(const Config &&) = delete;
+  Config &operator=(Config &&) = delete;
+  Config &operator=(const Config &&) = delete;
+
   HttpProxy downstream_http_proxy;
   HttpConfig http;
   Http2Config http2;