diff --git a/TODO b/TODO
index 64ea93b..e69de29 100644
--- a/TODO
+++ b/TODO
@@ -1 +0,0 @@
-- Try to switch from Arc to Box where possible
diff --git a/src/domain/acme/manager.rs b/src/domain/acme/manager.rs
index 2eb4b2c..3d57797 100644
--- a/src/domain/acme/manager.rs
+++ b/src/domain/acme/manager.rs
@@ -25,14 +25,14 @@ pub trait Manager: Sync + Send {
 }
 
 struct ManagerImpl {
-    store: sync::Arc<dyn acme::store::Store>,
+    store: Box<dyn acme::store::Store>,
     account: sync::Arc<acme2::Account>,
 }
 
 pub async fn new(
-    store: sync::Arc<dyn acme::store::Store>,
+    store: Box<dyn acme::store::Store>,
     contact_email: &str,
-) -> Result<sync::Arc<dyn Manager>, unexpected::Error> {
+) -> Result<Box<dyn Manager>, unexpected::Error> {
     let dir = acme2::DirectoryBuilder::new(LETS_ENCRYPT_URL.to_string())
         .build()
         .await
@@ -61,6 +61,7 @@ pub async fn new(
         .build()
         .await
         .or_unexpected_while("building account")?;
+
     let account_key: acme::PrivateKey = account
         .private_key()
         .as_ref()
@@ -71,7 +72,7 @@ pub async fn new(
         .set_account_key(&account_key)
         .or_unexpected_while("storing account key")?;
 
-    Ok(sync::Arc::new(ManagerImpl { store, account }))
+    Ok(Box::new(ManagerImpl { store, account }))
 }
 
 impl Manager for ManagerImpl {
diff --git a/src/domain/acme/store.rs b/src/domain/acme/store.rs
index 075327e..2e41217 100644
--- a/src/domain/acme/store.rs
+++ b/src/domain/acme/store.rs
@@ -1,6 +1,6 @@
 use std::io::{Read, Write};
 use std::str::FromStr;
-use std::{fs, path, sync};
+use std::{fs, path};
 
 use crate::domain::acme::{Certificate, PrivateKey};
 use crate::error::unexpected::{self, Mappable};
@@ -70,7 +70,7 @@ struct FSStore {
     dir_path: path::PathBuf,
 }
 
-pub fn new(dir_path: &path::Path) -> Result<sync::Arc<dyn Store>, unexpected::Error> {
+pub fn new(dir_path: &path::Path) -> Result<Box<dyn Store>, unexpected::Error> {
     vec![
         dir_path,
         dir_path.join("http01_challenge_keys").as_ref(),
@@ -82,7 +82,7 @@ pub fn new(dir_path: &path::Path) -> Result<sync::Arc<dyn Store>, unexpected::Er
     })
     .try_collect()?;
 
-    Ok(sync::Arc::new(FSStore {
+    Ok(Box::new(FSStore {
         dir_path: dir_path.into(),
     }))
 }
diff --git a/src/domain/config.rs b/src/domain/config.rs
index a24efdf..4315a7d 100644
--- a/src/domain/config.rs
+++ b/src/domain/config.rs
@@ -1,6 +1,6 @@
 use std::path::{Path, PathBuf};
 use std::str::FromStr;
-use std::{fs, io, sync};
+use std::{fs, io};
 
 use crate::error::unexpected::{self, Intoable, Mappable};
 use crate::{domain, origin};
@@ -49,9 +49,9 @@ struct FSStore {
     dir_path: PathBuf,
 }
 
-pub fn new(dir_path: &Path) -> io::Result<sync::Arc<dyn Store>> {
+pub fn new(dir_path: &Path) -> io::Result<Box<dyn Store>> {
     fs::create_dir_all(dir_path)?;
-    Ok(sync::Arc::new(FSStore {
+    Ok(Box::new(FSStore {
         dir_path: dir_path.into(),
     }))
 }
diff --git a/src/domain/manager.rs b/src/domain/manager.rs
index 44cc9c8..f18066a 100644
--- a/src/domain/manager.rs
+++ b/src/domain/manager.rs
@@ -147,9 +147,9 @@ pub trait Manager: Sync + Send + rustls::server::ResolvesServerCert {
 
 struct ManagerImpl {
     origin_store: Box<dyn origin::store::Store>,
-    domain_config_store: sync::Arc<dyn config::Store>,
+    domain_config_store: Box<dyn config::Store>,
     domain_checker: checker::DNSChecker,
-    acme_manager: Option<sync::Arc<dyn acme::manager::Manager>>,
+    acme_manager: Option<Box<dyn acme::manager::Manager>>,
 }
 
 async fn sync_origins(origin_store: &dyn origin::store::Store, canceller: CancellationToken) {
@@ -180,9 +180,9 @@ async fn sync_origins(origin_store: &dyn origin::store::Store, canceller: Cancel
 pub fn new(
     task_stack: &mut util::TaskStack<unexpected::Error>,
     origin_store: Box<dyn origin::store::Store>,
-    domain_config_store: sync::Arc<dyn config::Store>,
+    domain_config_store: Box<dyn config::Store>,
     domain_checker: checker::DNSChecker,
-    acme_manager: Option<sync::Arc<dyn acme::manager::Manager>>,
+    acme_manager: Option<Box<dyn acme::manager::Manager>>,
 ) -> sync::Arc<dyn Manager> {
     let manager = sync::Arc::new(ManagerImpl {
         origin_store,
diff --git a/src/main.rs b/src/main.rs
index 658d5f5..24a7c05 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,8 +5,8 @@ use futures::stream::StreamExt;
 use signal_hook_tokio::Signals;
 
 use std::net::SocketAddr;
+use std::path;
 use std::str::FromStr;
-use std::{path, sync};
 
 #[derive(Parser, Debug)]
 #[command(version)]
@@ -60,12 +60,6 @@ struct Cli {
     domain_acme_contact_email: Option<String>,
 }
 
-#[derive(Clone)]
-struct HTTPSParams {
-    https_listen_addr: SocketAddr,
-    domain_acme_manager: sync::Arc<dyn domiply::domain::acme::manager::Manager>,
-}
-
 #[tokio::main]
 async fn main() {
     let config = Cli::parse();
@@ -92,7 +86,7 @@ async fn main() {
     let domain_config_store = domiply::domain::config::new(&config.domain_config_store_dir_path)
         .expect("domain config store initialization failed");
 
-    let https_params = if let Some(https_listen_addr) = config.https_listen_addr {
+    let domain_acme_manager = if config.https_listen_addr.is_some() {
         let domain_acme_store_dir_path = config.domain_acme_store_dir_path.unwrap();
 
         let domain_acme_store = domiply::domain::acme::store::new(&domain_acme_store_dir_path)
@@ -102,15 +96,11 @@ async fn main() {
         // settings.
         let domain_acme_contact_email = config.domain_acme_contact_email.unwrap();
 
-        let domain_acme_manager =
+        Some(
             domiply::domain::acme::manager::new(domain_acme_store, &domain_acme_contact_email)
                 .await
-                .expect("domain acme manager initialization failed");
-
-        Some(HTTPSParams {
-            https_listen_addr,
-            domain_acme_manager,
-        })
+                .expect("domain acme manager initialization failed"),
+        )
     } else {
         None
     };
@@ -122,7 +112,7 @@ async fn main() {
         origin_store,
         domain_config_store,
         domain_checker,
-        https_params.as_ref().map(|p| p.domain_acme_manager.clone()),
+        domain_acme_manager,
     );
 
     let _ = domiply::service::http::new(
@@ -132,10 +122,12 @@ async fn main() {
         config.passphrase,
         config.http_listen_addr.clone(),
         config.http_domain.clone(),
-        https_params.map(|p| domiply::service::http::HTTPSParams {
-            listen_addr: p.https_listen_addr,
-            cert_resolver: domain_manager.clone(),
-        }),
+        config
+            .https_listen_addr
+            .map(|listen_addr| domiply::service::http::HTTPSParams {
+                listen_addr,
+                cert_resolver: domain_manager.clone(),
+            }),
     );
 
     let mut signals =