diff --git a/avro/src/bigdecimal.rs b/avro/src/bigdecimal.rs
index b8875350..7a6a3796 100644
--- a/avro/src/bigdecimal.rs
+++ b/avro/src/bigdecimal.rs
@@ -47,8 +47,7 @@ pub(crate) fn serialize_big_decimal(decimal: &BigDecimal) -> AvroResult<Vec<u8>>
     Ok(final_buffer)
 }
 
-pub(crate) fn deserialize_big_decimal(bytes: &Vec<u8>) -> AvroResult<BigDecimal> {
-    let mut bytes: &[u8] = bytes.as_slice();
+pub(crate) fn deserialize_big_decimal(mut bytes: &[u8]) -> AvroResult<BigDecimal> {
     let mut big_decimal_buffer = match decode_len(&mut bytes) {
         Ok(size) => vec![0u8; size],
         Err(err) => return Err(Details::BigDecimalLen(Box::new(err)).into()),
diff --git a/avro/src/schema/name.rs b/avro/src/schema/name.rs
index e572d8b2..b551584c 100644
--- a/avro/src/schema/name.rs
+++ b/avro/src/schema/name.rs
@@ -202,12 +202,12 @@ impl Alias {
         Name::new(name).map(Self)
     }
 
-    pub fn name(&self) -> String {
-        self.0.name.clone()
+    pub fn name(&self) -> &str {
+        &self.0.name
     }
 
-    pub fn namespace(&self) -> Namespace {
-        self.0.namespace.clone()
+    pub fn namespace(&self) -> &Namespace {
+        &self.0.namespace
     }
 
     pub fn fullname(&self, default_namespace: Namespace) -> String {
diff --git a/avro/src/serde/derive.rs b/avro/src/serde/derive.rs
index f384fb3f..7e3fb9e3 100644
--- a/avro/src/serde/derive.rs
+++ b/avro/src/serde/derive.rs
@@ -544,6 +544,7 @@ impl_schema!(f64, Schema::Double);
 impl_schema!(String, Schema::String);
 impl_schema!(str, Schema::String);
 impl_schema!(char, Schema::String);
+impl_schema!((), Schema::Null);
 
 macro_rules! impl_passthrough_schema (
     ($type:ty where T: AvroSchemaComponent + ?Sized $(+ $bound:tt)*) => (
@@ -943,4 +944,12 @@ mod tests {
 
         Ok(())
     }
+
+    #[test]
+    fn avro_rs_486_unit() -> TestResult {
+        let schema = <()>::get_schema();
+        assert_eq!(schema, Schema::Null);
+
+        Ok(())
+    }
 }
diff --git a/avro/src/serde/ser.rs b/avro/src/serde/ser.rs
index 76c6579f..efd6fe8b 100644
--- a/avro/src/serde/ser.rs
+++ b/avro/src/serde/ser.rs
@@ -182,7 +182,7 @@ impl ser::Serializer for Serializer {
 
     fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok, Self::Error> {
         match SER_BYTES_TYPE.get() {
-            BytesType::Bytes => Ok(Value::Bytes(v.to_owned())),
+            BytesType::Unset | BytesType::Bytes => Ok(Value::Bytes(v.to_owned())),
             BytesType::Fixed => Ok(Value::Fixed(v.len(), v.to_owned())),
         }
     }
diff --git a/avro/src/serde/ser_schema.rs b/avro/src/serde/ser_schema/mod.rs
similarity index 100%
rename from avro/src/serde/ser_schema.rs
rename to avro/src/serde/ser_schema/mod.rs
diff --git a/avro/src/serde/with.rs b/avro/src/serde/with.rs
index d5da6905..9d236d1f 100644
--- a/avro/src/serde/with.rs
+++ b/avro/src/serde/with.rs
@@ -22,7 +22,7 @@ thread_local! {
     /// [`Value::Bytes`] or [`Value::Fixed`].
     ///
     /// Relies on the fact that serde's serialization process is single-threaded.
-    pub(crate) static SER_BYTES_TYPE: Cell<BytesType> = const { Cell::new(BytesType::Bytes) };
+    pub(crate) static SER_BYTES_TYPE: Cell<BytesType> = const { Cell::new(BytesType::Unset) };
 
     /// A thread local that is used to decide if a [`Value::Bytes`] needs to be deserialized to
     /// a [`Vec`] or slice.
@@ -33,6 +33,7 @@ thread_local! {
 
 #[derive(Debug, Clone, Copy)]
 pub(crate) enum BytesType {
+    Unset,
     Bytes,
     Fixed,
 }
@@ -92,6 +93,7 @@ impl Drop for BorrowedGuard {
 ///
 /// [`apache_avro::serde::bytes_opt`]: bytes_opt
 pub mod bytes {
+    use super::BytesType;
     use std::collections::HashSet;
 
     use serde::{Deserializer, Serializer};
@@ -119,6 +121,7 @@ pub mod bytes {
     where
         S: Serializer,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::serialize(bytes, serializer)
     }
 
@@ -126,6 +129,7 @@ pub mod bytes {
     where
         D: Deserializer<'de>,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::deserialize(deserializer)
     }
 }
@@ -155,6 +159,7 @@ pub mod bytes {
 ///
 /// [`apache_avro::serde::bytes`]: bytes
 pub mod bytes_opt {
+    use super::BytesType;
     use serde::{Deserializer, Serializer};
     use std::{borrow::Borrow, collections::HashSet};
 
@@ -184,6 +189,7 @@ pub mod bytes_opt {
         S: Serializer,
         B: Borrow<[u8]> + serde_bytes::Serialize,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::serialize(bytes, serializer)
     }
 
@@ -191,6 +197,7 @@ pub mod bytes_opt {
     where
         D: Deserializer<'de>,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::deserialize(deserializer)
     }
 }
@@ -268,6 +275,7 @@ pub mod fixed {
     where
         D: Deserializer<'de>,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Fixed);
         serde_bytes::deserialize(deserializer)
     }
 }
@@ -342,6 +350,7 @@ pub mod fixed_opt {
     where
         D: Deserializer<'de>,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Fixed);
         serde_bytes::deserialize(deserializer)
     }
 }
@@ -373,6 +382,7 @@ pub mod fixed_opt {
 /// [`Value::Fixed`]: crate::types::Value::Fixed
 /// [`apache_avro::serde::slice_opt`]: slice_opt
 pub mod slice {
+    use super::BytesType;
     use std::collections::HashSet;
 
     use serde::{Deserializer, Serializer};
@@ -400,6 +410,7 @@ pub mod slice {
     where
         S: Serializer,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::serialize(bytes, serializer)
     }
 
@@ -407,6 +418,7 @@ pub mod slice {
     where
         D: Deserializer<'de>,
     {
+        let _bytes_guard = super::BytesTypeGuard::set(BytesType::Bytes);
         let _guard = super::BorrowedGuard::set(true);
         serde_bytes::deserialize(deserializer)
     }
@@ -439,6 +451,7 @@ pub mod slice {
 /// [`Value::Fixed`]: crate::types::Value::Fixed
 /// [`apache_avro::serde::slice`]: mod@slice
 pub mod slice_opt {
+    use super::BytesType;
     use serde::{Deserializer, Serializer};
     use std::{borrow::Borrow, collections::HashSet};
 
@@ -468,6 +481,7 @@ pub mod slice_opt {
         S: Serializer,
         B: Borrow<[u8]> + serde_bytes::Serialize,
     {
+        let _guard = super::BytesTypeGuard::set(BytesType::Bytes);
         serde_bytes::serialize(&bytes, serializer)
     }
 
@@ -475,6 +489,7 @@ pub mod slice_opt {
     where
         D: Deserializer<'de>,
     {
+        let _bytes_guard = super::BytesTypeGuard::set(BytesType::Bytes);
         let _guard = super::BorrowedGuard::set(true);
         serde_bytes::deserialize(deserializer)
     }
diff --git a/avro/src/util.rs b/avro/src/util.rs
index 8acbfa42..3127f8d1 100644
--- a/avro/src/util.rs
+++ b/avro/src/util.rs
@@ -127,8 +127,9 @@ fn encode_variable<W: Write>(mut zigzagged: u64, mut writer: W) -> AvroResult<us
         }
     }
     writer
-        .write(&buffer[..i])
-        .map_err(|e| Details::WriteBytes(e).into())
+        .write_all(&buffer[..i])
+        .map_err(Details::WriteBytes)?;
+    Ok(i)
 }
 
 /// Read a varint from the reader.
diff --git a/avro_test_helper/src/logger.rs b/avro_test_helper/src/logger.rs
index fe832389..738cdeed 100644
--- a/avro_test_helper/src/logger.rs
+++ b/avro_test_helper/src/logger.rs
@@ -60,6 +60,7 @@ pub fn clear_log_messages() {
     });
 }
 
+#[track_caller]
 pub fn assert_not_logged(unexpected_message: &str) {
     LOG_MESSAGES.with(|msgs| match msgs.borrow().last() {
         Some(last_log) if last_log == unexpected_message => {
@@ -69,6 +70,7 @@ pub fn assert_not_logged(unexpected_message: &str) {
     });
 }
 
+#[track_caller]
 pub fn assert_logged(expected_message: &str) {
     let mut deleted = false;
     LOG_MESSAGES.with(|msgs| {