diff --git a/src/binding/actix/headers.rs b/src/binding/actix/headers.rs
index 83eb8a0..867aeec 100644
--- a/src/binding/actix/headers.rs
+++ b/src/binding/actix/headers.rs
@@ -1,6 +1,6 @@
 macro_rules! str_to_header_value {
     ($header_value:expr) => {
-        HeaderValue::from_str($header_value.to_string().as_str()).map_err(|e| {
+        HeaderValue::from_str(&$header_value.to_string()).map_err(|e| {
             crate::message::Error::Other {
                 source: Box::new(e),
             }
diff --git a/src/binding/rdkafka/kafka_producer_record.rs b/src/binding/rdkafka/kafka_producer_record.rs
index 2c68e9b..0732395 100644
--- a/src/binding/rdkafka/kafka_producer_record.rs
+++ b/src/binding/rdkafka/kafka_producer_record.rs
@@ -45,36 +45,25 @@ impl Default for MessageRecord {
 }
 
 impl BinarySerializer<MessageRecord> for MessageRecord {
-    fn set_spec_version(mut self, spec_version: SpecVersion) -> Result<Self> {
-        self.headers = self.headers.add(SPEC_VERSION_HEADER, spec_version.as_str());
-
+    fn set_spec_version(mut self, sv: SpecVersion) -> Result<Self> {
+        self.headers = self.headers.add(SPEC_VERSION_HEADER, &sv.to_string());
         Ok(self)
     }
 
     fn set_attribute(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
-        self.headers = self.headers.add(
-            &attribute_header(PREFIX, name),
-            // TODO: return Option or Result
-            // .ok_or(crate::message::Error::UnknownAttribute {
-            //     name: String::from(name),
-            // })?
-            &value.to_string(),
-        );
-
+        let key = &attribute_header(PREFIX, name);
+        self.headers = self.headers.add(key, &value.to_string());
         Ok(self)
     }
 
     fn set_extension(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
-        self.headers = self
-            .headers
-            .add(&attribute_header(PREFIX, name), &value.to_string());
-
+        let key = &attribute_header(PREFIX, name);
+        self.headers = self.headers.add(key, &value.to_string());
         Ok(self)
     }
 
     fn end_with_data(mut self, bytes: Vec<u8>) -> Result<MessageRecord> {
         self.payload = Some(bytes);
-
         Ok(self)
     }
 
diff --git a/src/binding/reqwest/client_request.rs b/src/binding/reqwest/client_request.rs
index e590d69..79b9a49 100644
--- a/src/binding/reqwest/client_request.rs
+++ b/src/binding/reqwest/client_request.rs
@@ -21,22 +21,20 @@ impl RequestSerializer {
 }
 
 impl BinarySerializer<RequestBuilder> for RequestSerializer {
-    fn set_spec_version(mut self, spec_version: SpecVersion) -> Result<Self> {
-        self.req = self.req.header(SPEC_VERSION_HEADER, spec_version.as_str());
+    fn set_spec_version(mut self, spec_ver: SpecVersion) -> Result<Self> {
+        self.req = self.req.header(SPEC_VERSION_HEADER, spec_ver.to_string());
         Ok(self)
     }
 
     fn set_attribute(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
-        self.req = self
-            .req
-            .header(&attribute_header(PREFIX, name), value.to_string());
+        let key = &attribute_header(PREFIX, name);
+        self.req = self.req.header(key, value.to_string());
         Ok(self)
     }
 
     fn set_extension(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
-        self.req = self
-            .req
-            .header(&attribute_header(PREFIX, name), value.to_string());
+        let key = &attribute_header(PREFIX, name);
+        self.req = self.req.header(key, value.to_string());
         Ok(self)
     }
 
diff --git a/src/binding/warp/server_response.rs b/src/binding/warp/server_response.rs
index 030eca3..49af04e 100644
--- a/src/binding/warp/server_response.rs
+++ b/src/binding/warp/server_response.rs
@@ -32,7 +32,7 @@ impl BinarySerializer<Response> for ResponseSerializer {
     fn set_spec_version(mut self, spec_version: SpecVersion) -> Result<Self> {
         self.builder = self.builder.header(
             SPEC_VERSION_HEADER,
-            HeaderValue::try_from(spec_version.to_string().as_str()).map_err(|e| {
+            HeaderValue::try_from(spec_version.to_string()).map_err(|e| {
                 crate::message::Error::Other {
                     source: Box::new(e),
                 }
@@ -44,7 +44,7 @@ impl BinarySerializer<Response> for ResponseSerializer {
     fn set_attribute(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
         self.builder = self.builder.header(
             &attribute_header(PREFIX, name),
-            HeaderValue::try_from(value.to_string().as_str()).map_err(|e| {
+            HeaderValue::try_from(&value.to_string()).map_err(|e| {
                 crate::message::Error::Other {
                     source: Box::new(e),
                 }
@@ -56,7 +56,7 @@ impl BinarySerializer<Response> for ResponseSerializer {
     fn set_extension(mut self, name: &str, value: MessageAttributeValue) -> Result<Self> {
         self.builder = self.builder.header(
             &attribute_header(PREFIX, name),
-            HeaderValue::try_from(value.to_string().as_str()).map_err(|e| {
+            HeaderValue::try_from(&value.to_string()).map_err(|e| {
                 crate::message::Error::Other {
                     source: Box::new(e),
                 }