diff --git a/acmed/src/endpoint.rs b/acmed/src/endpoint.rs
index ce7bc4a..89e5ea6 100644
--- a/acmed/src/endpoint.rs
+++ b/acmed/src/endpoint.rs
@@ -130,7 +130,7 @@ fn is_duration_chr(c: char) -> bool {
 
 fn get_multiplicator(input: &str) -> IResult<&str, u64> {
     let (input, nb) = take_while_m_n(1, 1, is_duration_chr)(input)?;
-    let mult = match nb.chars().nth(0) {
+    let mult = match nb.chars().next() {
         Some('s') => 1,
         Some('m') => 60,
         Some('h') => 3_600,
diff --git a/acmed/src/http.rs b/acmed/src/http.rs
index 7bdcbff..ccedc98 100644
--- a/acmed/src/http.rs
+++ b/acmed/src/http.rs
@@ -34,7 +34,7 @@ fn update_nonce(endpoint: &mut Endpoint, response: &Response) -> Result<(), Erro
             let msg = format!("{}: invalid nonce.", &nonce);
             return Err(msg.into());
         }
-        endpoint.nonce = Some(nonce.to_string());
+        endpoint.nonce = Some(nonce);
     }
     Ok(())
 }
diff --git a/acmed/src/main_event_loop.rs b/acmed/src/main_event_loop.rs
index 5dbd743..b4ddb00 100644
--- a/acmed/src/main_event_loop.rs
+++ b/acmed/src/main_event_loop.rs
@@ -64,10 +64,9 @@ impl MainEventLoop {
                 env: crt.env.to_owned(),
                 id: i + 1,
             };
-            if !endpoints.contains_key(&endpoint_name) {
-                let ep = Arc::new(RwLock::new(endpoint));
-                endpoints.insert(endpoint_name, ep);
-            }
+            endpoints
+                .entry(endpoint_name)
+                .or_insert_with(|| Arc::new(RwLock::new(endpoint)));
             init_account(&cert)?;
             certs.push(cert);
         }
diff --git a/acmed/src/storage.rs b/acmed/src/storage.rs
index 6acad59..2d6b728 100644
--- a/acmed/src/storage.rs
+++ b/acmed/src/storage.rs
@@ -135,7 +135,7 @@ fn write_file(cert: &Certificate, file_type: FileType, data: &[u8]) -> Result<()
     let mut hook_data = FileStorageHookData {
         file_name,
         file_directory,
-        file_path: path.to_path_buf(),
+        file_path: path.to_owned(),
         env: HashMap::new(),
     };
     hook_data.set_env(&cert.env);