diff --git a/examples/certificate_client.rs b/examples/certificate_client.rs
index f0fdad87..709ba03f 100644
--- a/examples/certificate_client.rs
+++ b/examples/certificate_client.rs
@@ -54,7 +54,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let client = new_client()?;
 
     let options = NotificationOptions {
-        apns_topic: topic.as_ref().map(|s| &**s),
+        apns_topic: topic.as_deref(),
         ..Default::default()
     };
 
diff --git a/examples/token_client.rs b/examples/token_client.rs
index cbe5c859..32c3c0af 100644
--- a/examples/token_client.rs
+++ b/examples/token_client.rs
@@ -51,7 +51,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     let client = Client::token(&mut private_key, key_id, team_id, endpoint).unwrap();
 
     let options = NotificationOptions {
-        apns_topic: topic.as_ref().map(|s| &**s),
+        apns_topic: topic.as_deref(),
         ..Default::default()
     };
 
diff --git a/src/client.rs b/src/client.rs
index d44b3cef..8339749c 100644
--- a/src/client.rs
+++ b/src/client.rs
@@ -149,7 +149,7 @@ impl Client {
             builder = builder.header("apns-expiration", apns_expiration.to_string().as_bytes());
         }
         if let Some(ref apns_collapse_id) = payload.options.apns_collapse_id {
-            builder = builder.header("apns-collapse-id", apns_collapse_id.value.to_string().as_bytes());
+            builder = builder.header("apns-collapse-id", apns_collapse_id.value.as_bytes());
         }
         if let Some(apns_topic) = payload.options.apns_topic {
             builder = builder.header("apns-topic", apns_topic.as_bytes());
diff --git a/src/error.rs b/src/error.rs
index 5f167ba2..a4ed649d 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,5 +1,4 @@
-//! Error and result module
-
+///! Error and result module
 use crate::{response::Response, signer::SignerError};
 use std::io;
 use thiserror::Error;
diff --git a/src/request/notification.rs b/src/request/notification.rs
index 717c0717..354f556e 100644
--- a/src/request/notification.rs
+++ b/src/request/notification.rs
@@ -1,5 +1,4 @@
-//! The `aps` notification content builders
-
+///! The `aps` notification content builders
 mod default;
 mod options;
 mod web;
diff --git a/src/request/notification/default.rs b/src/request/notification/default.rs
index ab3834eb..0b07f1fe 100644
--- a/src/request/notification/default.rs
+++ b/src/request/notification/default.rs
@@ -3,7 +3,7 @@ use crate::request::payload::{APSAlert, Payload, APS};
 
 use std::{borrow::Cow, collections::BTreeMap};
 
-#[derive(Serialize, Debug, Clone)]
+#[derive(Deserialize, Serialize, Debug, Clone)]
 #[serde(rename_all = "kebab-case")]
 pub struct DefaultAlert<'a> {
     #[serde(skip_serializing_if = "Option::is_none")]
diff --git a/src/request/notification/options.rs b/src/request/notification/options.rs
index d821c5aa..1fb7c260 100644
--- a/src/request/notification/options.rs
+++ b/src/request/notification/options.rs
@@ -20,7 +20,7 @@ impl<'a> CollapseId<'a> {
 }
 
 /// Headers to specify options to the notification.
-#[derive(Debug, Clone, Default)]
+#[derive(Debug, Default, Clone)]
 pub struct NotificationOptions<'a> {
     /// A canonical UUID that identifies the notification. If there is an error
     /// sending the notification, APNs uses this value to identify the
diff --git a/src/request/notification/web.rs b/src/request/notification/web.rs
index 2cc86bcd..a0ff341c 100644
--- a/src/request/notification/web.rs
+++ b/src/request/notification/web.rs
@@ -2,7 +2,7 @@ use crate::request::notification::{NotificationBuilder, NotificationOptions};
 use crate::request::payload::{APSAlert, Payload, APS};
 use std::collections::BTreeMap;
 
-#[derive(Serialize, Debug, Clone)]
+#[derive(Serialize, Deserialize, Debug, Clone)]
 #[serde(rename_all = "kebab-case")]
 pub struct WebPushAlert<'a> {
     pub title: &'a str,
@@ -104,7 +104,7 @@ mod tests {
                 title: "Hello",
                 body: "world",
             },
-            &vec!["arg1"],
+            &["arg1"],
         )
         .build("device-token", Default::default())
         .to_json_string()
diff --git a/src/request/payload.rs b/src/request/payload.rs
index dcb013e4..71c7c3f7 100644
--- a/src/request/payload.rs
+++ b/src/request/payload.rs
@@ -1,5 +1,4 @@
-//! Payload with `aps` and custom data
-
+///! Payload with `aps` and custom data
 use crate::error::Error;
 use crate::request::notification::{DefaultAlert, NotificationOptions, WebPushAlert};
 use erased_serde::Serialize;
@@ -91,7 +90,7 @@ impl<'a> Payload<'a> {
 }
 
 /// The pre-defined notification data.
-#[derive(Serialize, Debug, Clone)]
+#[derive(Serialize, Default, Debug, Clone)]
 #[serde(rename_all = "kebab-case")]
 #[allow(clippy::upper_case_acronyms)]
 pub struct APS<'a> {