diff --git a/packages/rxdart/lib/src/transformers/default_if_empty.dart b/packages/rxdart/lib/src/transformers/default_if_empty.dart
index fb9deedf..ed9fc204 100644
--- a/packages/rxdart/lib/src/transformers/default_if_empty.dart
+++ b/packages/rxdart/lib/src/transformers/default_if_empty.dart
@@ -47,7 +47,8 @@ class DefaultIfEmptyStreamTransformer<S> extends StreamTransformerBase<S, S> {
       stream, (sink) => _DefaultIfEmptyStreamSink<S>(sink, defaultValue));
 }
 
-///
+/// Extend the Stream class with the ability to emit a single default item if the
+/// source Stream emits nothing.
 extension DefaultIfEmptyExtension<T> on Stream<T> {
   /// Emit items from the source Stream, or a single default item if the source
   /// Stream emits nothing.