diff --git a/opentelemetry-api/src/trace/tracer.rs b/opentelemetry-api/src/trace/tracer.rs
index 66b03ab2cf..e36d32c5c5 100644
--- a/opentelemetry-api/src/trace/tracer.rs
+++ b/opentelemetry-api/src/trace/tracer.rs
@@ -332,7 +332,7 @@ impl SpanBuilder {
     /// via an [`OrderMap`] instance.
     pub fn with_attributes<I>(self, attributes: I) -> Self
     where
-        I: IntoIterator<Item = KeyValue>
+        I: IntoIterator<Item = KeyValue>,
     {
         SpanBuilder {
             attributes: Some(OrderMap::from_iter(attributes.into_iter())),