diff --git a/packages/flutter/lib/src/services/font_loader.dart b/packages/flutter/lib/src/services/font_loader.dart
index 423188a2c0..709920d70c 100644
--- a/packages/flutter/lib/src/services/font_loader.dart
+++ b/packages/flutter/lib/src/services/font_loader.dart
@@ -65,6 +65,10 @@ class FontLoader {
     return Future.wait(loadFutures.toList());
   }
 
+  /// Hook called to load a font asset into the engine.
+  ///
+  /// Subclasses may override this to replace the default loading logic with
+  /// custom logic (for example, to mock the underlying engine API in tests).
   @protected
   @visibleForTesting
   Future<void> loadFont(Uint8List list, String family) {