diff --git a/config-example.toml b/config-example.toml
index 5203cc0..61e14e9 100644
--- a/config-example.toml
+++ b/config-example.toml
@@ -44,7 +44,8 @@ reverse_proxy = [
   ] },
 ]
 # Optional: TLS setting. if https_port is specified and tls is true above, this must be given.
-tls = { https_redirection = true, tls_cert_path = 'localhost.pem', tls_cert_key_path = 'localhost.pem' }
+tls = { https_redirection = true, tls_cert_path = '/certs/localhost.pem', tls_cert_key_path = '/certs/localhost.pem' } # for docker volume mounted certs
+#tls = { https_redirection = true, tls_cert_path = './localhost.pem', tls_cert_key_path = './localhost.pem' }          # for local
 
 
 ## List of destinations to send data to.
diff --git a/docker-bin/run.sh b/docker-bin/run.sh
index e89d790..b02efcb 100644
--- a/docker-bin/run.sh
+++ b/docker-bin/run.sh
@@ -51,6 +51,13 @@ EOF
 cp -p /etc/cron.daily/logrotate /etc/cron.hourly/
 service cron start
 
+# debug level logging
+  LOG_LEVEL=info
+  if [ ${DEBUG} ]; then
+    echo "Logging in debug mode"
+    LOG_LEVEL=debug
+  fi
+
 echo "Start rpxy"
 
-RUST_LOG=info /opt/rpxy/sbin/rpxy --config ${CONFIG_FILE}
+RUST_LOG=${LOG_LEVEL} /opt/rpxy/sbin/rpxy --config ${CONFIG_FILE}
diff --git a/docker-compose.yml b/docker-compose.yml
index 0cac872..422c9d7 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -9,8 +9,10 @@ services:
       - 127.0.0.1:8443:8443
     build:
       context: ./
+    environment:
+      - DEBUG=true
     tty: false
     privileged: true
     volumes:
-      - ./example-certs:/tmp/certs:ro
+      - ./localhost.pem:/certs/localhost.pem:ro
       - ./config-example.toml:/etc/rpxy.toml:ro
diff --git a/src/proxy/proxy_handler.rs b/src/proxy/proxy_handler.rs
index dcc73ef..cc6dff9 100644
--- a/src/proxy/proxy_handler.rs
+++ b/src/proxy/proxy_handler.rs
@@ -118,13 +118,19 @@ where
           let mut response_upgraded = res_backend
             .extensions_mut()
             .remove::<hyper::upgrade::OnUpgrade>()
-            .expect("Response does not have an upgrade extension")
+            .ok_or_else(|| anyhow!("Response does not have an upgrade extension"))? // TODO: any response code?
             .await?;
+          // TODO: H3で死ぬことがある
+          // thread 'rpxy' panicked at 'Failed to upgrade request: hyper::Error(User(ManualUpgrade))', src/proxy/proxy_handler.rs:124:63
           tokio::spawn(async move {
-            let mut request_upgraded = request_upgraded.await.expect("Failed to upgrade request");
+            let mut request_upgraded = request_upgraded.await.map_err(|e| {
+              error!("Failed to upgrade request: {}", e);
+              anyhow!("Failed to upgrade request: {}", e)
+            })?; // TODO: any response code?
             copy_bidirectional(&mut response_upgraded, &mut request_upgraded)
               .await
-              .expect("Coping between upgraded connections failed");
+              .map_err(|e| anyhow!("Coping between upgraded connections failed: {}", e))?; // TODO: any response code?
+            Ok(()) as Result<()>
           });
           Ok(res_backend)
         } else {
diff --git a/src/proxy/proxy_tls.rs b/src/proxy/proxy_tls.rs
index 39fd1cb..a97d712 100644
--- a/src/proxy/proxy_tls.rs
+++ b/src/proxy/proxy_tls.rs
@@ -110,44 +110,47 @@ where
       loop {
         // TODO: Not sure if this properly works to handle multiple "server_name"s to host multiple hosts.
         // peek() should work for that.
-        if let Some(peeked_conn) = std::pin::Pin::new(&mut p).peek_mut().await {
+        let success = if let Some(peeked_conn) = std::pin::Pin::new(&mut p).peek_mut().await {
           let hsd = peeked_conn.handshake_data().await;
           let hsd_downcast = hsd?
             .downcast::<quinn::crypto::rustls::HandshakeData>()
             .unwrap();
-          let svn = if let Some(sni) = hsd_downcast.server_name {
-            sni
+          if let Some(svn) = hsd_downcast.server_name {
+            if let Some(new_server_crypto) = self.fetch_server_crypto(&svn) {
+              // Set ServerConfig::set_server_config for given SNI
+              let mut new_server_config_h3 =
+                quinn::ServerConfig::with_crypto(Arc::new(new_server_crypto));
+              if svn == "localhost" {
+                new_server_config_h3.concurrent_connections(512);
+              }
+              info!(
+                "HTTP/3 connection incoming (SNI {:?}): Overwrite ServerConfig",
+                svn
+              );
+              endpoint.set_server_config(Some(new_server_config_h3));
+              true
+            } else {
+              false
+            }
           } else {
             debug!("HTTP/3 no SNI is given");
-            continue;
-          };
-          let new_server_crypto = if let Some(p) = self.fetch_server_crypto(&svn) {
-            p
-          } else {
-            continue;
-          };
-          // Set ServerConfig::set_server_config for given SNI
-          let mut new_server_config_h3 =
-            quinn::ServerConfig::with_crypto(Arc::new(new_server_crypto));
-          if svn == "localhost" {
-            new_server_config_h3.concurrent_connections(512);
+            false
           }
-          info!(
-            "HTTP/3 connection incoming (SNI {:?}): Overwrite ServerConfig",
-            svn
-          );
-          endpoint.set_server_config(Some(new_server_config_h3));
-        }
+        } else {
+          false
+        };
 
         // Then acquire actual connection
         let peekable_incoming = std::pin::Pin::new(&mut p);
         if let Some(conn) = peekable_incoming.get_mut().next().await {
-          let fut = self.clone().client_serve_h3(conn);
-          self.globals.runtime_handle.spawn(async {
-            if let Err(e) = fut.await {
-              warn!("QUIC or HTTP/3 connection failed: {}", e)
-            }
-          });
+          if success {
+            let fut = self.clone().client_serve_h3(conn);
+            self.globals.runtime_handle.spawn(async {
+              if let Err(e) = fut.await {
+                warn!("QUIC or HTTP/3 connection failed: {}", e)
+              }
+            });
+          }
         } else {
           break;
         }