diff --git a/lib/src/api/trace/tracer.dart b/lib/src/api/trace/tracer.dart
index a9087f5a..c09152dc 100644
--- a/lib/src/api/trace/tracer.dart
+++ b/lib/src/api/trace/tracer.dart
@@ -17,9 +17,10 @@ abstract class Tracer {
   /// The [api.Span] is created with the provided name and as a child of any
   /// existing span context found in the passed context.
   api.Span startSpan(String name,
-      {api.Context context,
-      api.SpanKind kind,
-      List<api.Attribute> attributes,
-      List<api.SpanLink> links,
-      Int64 startTime});
+      {api.Context? context,
+      api.SpanKind kind = api.SpanKind.internal,
+      List<api.Attribute> attributes = const [],
+      List<api.SpanLink> links = const [],
+      Int64? startTime,
+      bool newRoot = false});
 }