diff --git a/src/filter/custom.rs b/src/filter/custom.rs
index 0553e7f..a5cdb70 100644
--- a/src/filter/custom.rs
+++ b/src/filter/custom.rs
@@ -20,8 +20,7 @@ use crate::filter::Filter;
 use crate::filter::FilterResult;
 
 pub struct CustomFilter {
-    #[allow(clippy::type_complexity)]
-    f: Box<dyn Fn(&log::Metadata) -> FilterResult + Send + Sync + 'static>,
+    f: Box<dyn Fn(&Metadata) -> FilterResult + Send + Sync + 'static>,
 }
 
 impl Debug for CustomFilter {
@@ -31,7 +30,7 @@ impl Debug for CustomFilter {
 }
 
 impl CustomFilter {
-    pub fn new(filter: impl Fn(&log::Metadata) -> FilterResult + Send + Sync + 'static) -> Self {
+    pub fn new(filter: impl Fn(&Metadata) -> FilterResult + Send + Sync + 'static) -> Self {
         CustomFilter {
             f: Box::new(filter),
         }
diff --git a/src/layout/custom.rs b/src/layout/custom.rs
index ad177c0..a5a149c 100644
--- a/src/layout/custom.rs
+++ b/src/layout/custom.rs
@@ -16,27 +16,30 @@ use std::fmt::Arguments;
 use std::fmt::Debug;
 use std::fmt::Formatter;
 
+use log::Record;
+
 use crate::layout::Layout;
 
+// TODO(tisonkun): use trait alias when it's stable - https://github.com/rust-lang/rust/issues/41517
+//  then we can use the alias for both `dyn` and `impl`.
+type FormatFunction = dyn Fn(&Record, &dyn Fn(Arguments) -> anyhow::Result<()>) -> anyhow::Result<()>
+    + Send
+    + Sync
+    + 'static;
+
 pub struct CustomLayout {
-    #[allow(clippy::type_complexity)]
-    f: Box<
-        dyn Fn(&log::Record, &dyn Fn(Arguments) -> anyhow::Result<()>) -> anyhow::Result<()>
-            + Send
-            + Sync
-            + 'static,
-    >,
+    f: Box<FormatFunction>,
 }
 
 impl Debug for CustomLayout {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut Formatter) -> std::fmt::Result {
         write!(f, "CustomLayout {{ ... }}")
     }
 }
 
 impl CustomLayout {
     pub fn new(
-        layout: impl Fn(&log::Record, &dyn Fn(Arguments) -> anyhow::Result<()>) -> anyhow::Result<()>
+        layout: impl Fn(&Record, &dyn Fn(Arguments) -> anyhow::Result<()>) -> anyhow::Result<()>
             + Send
             + Sync
             + 'static,
@@ -46,7 +49,7 @@ impl CustomLayout {
         }
     }
 
-    pub(crate) fn format<F>(&self, record: &log::Record, f: &F) -> anyhow::Result<()>
+    pub(crate) fn format<F>(&self, record: &Record, f: &F) -> anyhow::Result<()>
     where
         F: Fn(Arguments) -> anyhow::Result<()>,
     {
diff --git a/src/layout/json.rs b/src/layout/json.rs
index df52625..30d716b 100644
--- a/src/layout/json.rs
+++ b/src/layout/json.rs
@@ -13,11 +13,10 @@
 // limitations under the License.
 
 use std::fmt::Arguments;
-use std::path::Path;
 use std::time::SystemTime;
 
+use humantime::Rfc3339Timestamp;
 use log::Record;
-use serde::Deserialize;
 use serde::Serialize;
 use serde_json::Map;
 use serde_json::Value;
@@ -44,17 +43,33 @@ impl<'a, 'kvs> log::kv::Visitor<'kvs> for KvCollector<'a> {
     }
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Serialize)]
 struct RecordLine<'a> {
-    timestamp: String,
-    level: String,
+    #[serde(serialize_with = "serialize_timestamp")]
+    timestamp: Rfc3339Timestamp,
+    level: &'a str,
     module_path: &'a str,
     file: &'a str,
     line: u32,
-    message: String,
+    #[serde(serialize_with = "serialize_args")]
+    message: &'a Arguments<'a>,
     kvs: Map<String, Value>,
 }
 
+fn serialize_args<S>(args: &Arguments, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    serializer.collect_str(args)
+}
+
+fn serialize_timestamp<S>(timestamp: &Rfc3339Timestamp, serializer: S) -> Result<S::Ok, S::Error>
+where
+    S: serde::Serializer,
+{
+    serializer.collect_str(&format_args!("{timestamp}"))
+}
+
 impl JsonLayout {
     pub(crate) fn format<F>(&self, record: &Record, f: &F) -> anyhow::Result<()>
     where
@@ -64,18 +79,13 @@ impl JsonLayout {
         let mut visitor = KvCollector { kvs: &mut kvs };
         record.key_values().visit(&mut visitor)?;
 
-        let timestamp = humantime::format_rfc3339_micros(SystemTime::now());
         let record_line = RecordLine {
-            timestamp: format!("{timestamp}"),
-            level: record.level().to_string(),
-            module_path: record.module_path().unwrap_or(""),
-            file: record
-                .file()
-                .and_then(|file| Path::new(file).file_name())
-                .and_then(|name| name.to_str())
-                .unwrap_or_default(),
+            timestamp: humantime::format_rfc3339_micros(SystemTime::now()),
+            level: record.level().as_str(),
+            module_path: record.module_path().unwrap_or_default(),
+            file: record.file().unwrap_or_default(),
             line: record.line().unwrap_or(0),
-            message: record.args().to_string(),
+            message: record.args(),
             kvs,
         };
 
diff --git a/src/layout/text.rs b/src/layout/text.rs
index a0691e8..5fcc57a 100644
--- a/src/layout/text.rs
+++ b/src/layout/text.rs
@@ -13,7 +13,6 @@
 // limitations under the License.
 
 use std::fmt::Arguments;
-use std::path::Path;
 use std::time::SystemTime;
 
 use colored::Color;
@@ -65,12 +64,8 @@ impl TextLayout {
 
         let time = humantime::format_rfc3339_micros(SystemTime::now());
         let level = ColoredString::from(record.level().to_string()).color(color);
-        let module = record.module_path().unwrap_or("");
-        let file = record
-            .file()
-            .and_then(|file| Path::new(file).file_name())
-            .and_then(|name| name.to_str())
-            .unwrap_or_default();
+        let module = record.module_path().unwrap_or_default();
+        let file = record.file().unwrap_or_default();
         let line = record.line().unwrap_or(0);
         let message = record.args();
         let kvs = KvDisplay::new(record.key_values());