diff --git a/src/append/fastrace.rs b/src/append/fastrace.rs
index e069739..f252464 100644
--- a/src/append/fastrace.rs
+++ b/src/append/fastrace.rs
@@ -12,12 +12,13 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+use std::borrow::Cow;
+
 use jiff::Zoned;
 use log::Record;
 
 use crate::append::Append;
 use crate::layout::collect_kvs;
-use crate::layout::KvDisplay;
 
 /// An appender that adds log records to fastrace as an event associated to the current span.
 #[derive(Default, Debug, Clone)]
@@ -27,8 +28,16 @@ impl Append for FastraceEvent {
     fn append(&self, record: &Record) -> anyhow::Result<()> {
         let message = format!("{}", record.args());
         fastrace::Event::add_to_local_parent(message, || {
-            [("level", record.level()), ("timestamp", Zoned::now())]
-                .chain(collect_kvs(record.key_values()))
+            [
+                (Cow::from("level"), Cow::from(record.level().as_str())),
+                (Cow::from("timestamp"), Cow::from(Zoned::now().to_string())),
+            ]
+            .into_iter()
+            .chain(
+                collect_kvs(record.key_values())
+                    .into_iter()
+                    .map(|(k, v)| (Cow::from(k), Cow::from(v))),
+            )
         });
         Ok(())
     }