diff --git a/lib/src/model.dart b/lib/src/model.dart
index eed06ba..39ac7ae 100644
--- a/lib/src/model.dart
+++ b/lib/src/model.dart
@@ -5671,7 +5671,7 @@
       lib ??= Library(e.enclosingElement.library, packageGraph);
       // (TODO:keertip) Find a better way to exclude members of extensions
       //  when libraries are specified using the "--include" flag
-      if (lib?.isDocumented) {
+      if (lib?.isDocumented == true) {
         return ModelElement.from(e, lib, packageGraph);
       }
     }
diff --git a/test/model_test.dart b/test/model_test.dart
index 031618f..10e4364 100644
--- a/test/model_test.dart
+++ b/test/model_test.dart
@@ -2100,13 +2100,12 @@
   });
 
   group('Extension', () {
-    Extension ext, anExt, fancyList;
+    Extension ext, fancyList;
     Method s;
     List<Extension> extensions;
 
     setUpAll(() {
       ext = exLibrary.extensions.firstWhere((e) => e.name == 'AppleExtension');
-      anExt = exLibrary.extensions.firstWhere((e) => e.name == 'AnExtension');
       fancyList = exLibrary.extensions.firstWhere((e) => e.name == 'FancyList');
       extensions = exLibrary.publicExtensions.toList();
     });