diff --git a/lib/src/generator/generator_utils.dart b/lib/src/generator/generator_utils.dart
index 73ba95edbd..94c4c9aef5 100644
--- a/lib/src/generator/generator_utils.dart
+++ b/lib/src/generator/generator_utils.dart
@@ -6,7 +6,6 @@ import 'dart:convert';
 
 import 'package:collection/collection.dart';
 import 'package:dartdoc/src/model/directives/categorization.dart';
-import 'package:dartdoc/src/model/enclosed_element.dart';
 import 'package:dartdoc/src/model/indexable.dart';
 import 'package:dartdoc/src/model/model_element.dart';
 
@@ -34,30 +33,28 @@ String generateCategoryJson(Iterable<Categorization> categories, bool pretty) {
 }
 
 /// Generates the text of the search index file (`index.json`) containing
-/// [indexedItems] and [packageOrder].
+/// [indexedElements] and [packageOrder].
 ///
 /// Passing `pretty: true` will use a [JsonEncoder] with a single-space indent.
 String generateSearchIndexJson(Iterable<Indexable> indexedElements,
     {required List<String> packageOrder, required bool pretty}) {
   final indexItems = [
-    for (final indexable
-        in indexedElements.sorted(_compareElementRepresentations))
+    for (final item in indexedElements.sorted(_compareElementRepresentations))
       {
-        'name': indexable.name,
-        'qualifiedName': indexable.fullyQualifiedName,
-        'href': indexable.href,
-        'kind': indexable.kind.index,
+        'name': item.name,
+        'qualifiedName': item.fullyQualifiedName,
+        'href': item.href,
+        'kind': item.kind.index,
         // TODO(srawlins): Only include this for [Inheritable] items.
-        'overriddenDepth': indexable.overriddenDepth,
-        if (indexable is ModelElement)
-          'packageRank': _packageRank(packageOrder, indexable),
-        if (indexable is ModelElement)
-          'desc': _removeHtmlTags(indexable.oneLineDoc),
-        if (indexable is EnclosedElement)
+        'overriddenDepth': item.overriddenDepth,
+        if (item is ModelElement)
+          'packageRank': _packageRank(packageOrder, item),
+        if (item is ModelElement) 'desc': _removeHtmlTags(item.oneLineDoc),
+        if (item case ModelElement(:var enclosingElement?))
           'enclosedBy': {
-            'name': indexable.enclosingElement.name,
-            'kind': indexable.enclosingElement.kind.index,
-            'href': indexable.enclosingElement.href,
+            'name': enclosingElement.name,
+            'kind': enclosingElement.kind.index,
+            'href': enclosingElement.href,
           },
       }
   ];
@@ -114,7 +111,7 @@ final _htmlTagPattern =
     RegExp(r'<[^>]*>', multiLine: true, caseSensitive: true);
 
 // Compares two elements, first by fully qualified name, then by kind.
-int _compareElementRepresentations<T extends Indexable>(T a, T b) {
+int _compareElementRepresentations(Indexable a, Indexable b) {
   final value = compareNatural(a.fullyQualifiedName, b.fullyQualifiedName);
   if (value == 0) {
     return compareNatural(a.kind.toString(), b.kind.toString());
diff --git a/lib/src/generator/templates.runtime_renderers.dart b/lib/src/generator/templates.runtime_renderers.dart
index 6b606f4a78..b68e7a6f63 100644
--- a/lib/src/generator/templates.runtime_renderers.dart
+++ b/lib/src/generator/templates.runtime_renderers.dart
@@ -2084,8 +2084,8 @@ class _Renderer_Constructor extends RendererBase<Constructor> {
           CT_,
           () => {
                 ..._Renderer_ModelElement.propertyMap<CT_>(),
-                ..._Renderer_TypeParameters.propertyMap<CT_>(),
                 ..._Renderer_ContainerMember.propertyMap<CT_>(),
+                ..._Renderer_TypeParameters.propertyMap<CT_>(),
                 'aboveSidebarPath': Property(
                   getValue: (CT_ c) => c.aboveSidebarPath,
                   renderVariable:
@@ -3456,29 +3456,6 @@ class _Renderer_ContainerMember extends RendererBase<ContainerMember> {
                         parent: r);
                   },
                 ),
-                'definingEnclosingContainer': Property(
-                  getValue: (CT_ c) => c.definingEnclosingContainer,
-                  renderVariable:
-                      (CT_ c, Property<CT_> self, List<String> remainingNames) {
-                    if (remainingNames.isEmpty) {
-                      return self.getValue(c).toString();
-                    }
-                    var name = remainingNames.first;
-                    var nextProperty =
-                        _Renderer_Container.propertyMap().getValue(name);
-                    return nextProperty.renderVariable(
-                        self.getValue(c) as Container,
-                        nextProperty,
-                        [...remainingNames.skip(1)]);
-                  },
-                  isNullValue: (CT_ c) => false,
-                  renderValue: (CT_ c, RendererBase<CT_> r,
-                      List<MustachioNode> ast, StringSink sink) {
-                    _render_Container(
-                        c.definingEnclosingContainer, ast, r.template, sink,
-                        parent: r);
-                  },
-                ),
                 'enclosingElement': Property(
                   getValue: (CT_ c) => c.enclosingElement,
                   renderVariable:
diff --git a/lib/src/model/accessor.dart b/lib/src/model/accessor.dart
index b9b8fa2780..d1e9aa250c 100644
--- a/lib/src/model/accessor.dart
+++ b/lib/src/model/accessor.dart
@@ -16,7 +16,7 @@ import 'package:dartdoc/src/utils.dart';
 import 'package:dartdoc/src/warnings.dart';
 
 /// Getters and setters.
-class Accessor extends ModelElement implements EnclosedElement {
+class Accessor extends ModelElement {
   @override
   final PropertyAccessorElement element;
 
diff --git a/lib/src/model/constructor.dart b/lib/src/model/constructor.dart
index e69fd4d63e..ecbcb99c11 100644
--- a/lib/src/model/constructor.dart
+++ b/lib/src/model/constructor.dart
@@ -8,9 +8,7 @@ import 'package:dartdoc/src/element_type.dart';
 import 'package:dartdoc/src/model/comment_referable.dart';
 import 'package:dartdoc/src/model/model.dart';
 
-class Constructor extends ModelElement
-    with TypeParameters, ContainerMember
-    implements EnclosedElement {
+class Constructor extends ModelElement with ContainerMember, TypeParameters {
   @override
   final ConstructorElement element;
 
diff --git a/lib/src/model/container_member.dart b/lib/src/model/container_member.dart
index 5dc78ca08c..af8b9e08c3 100644
--- a/lib/src/model/container_member.dart
+++ b/lib/src/model/container_member.dart
@@ -4,9 +4,10 @@
 
 import 'package:dartdoc/src/model/attribute.dart';
 import 'package:dartdoc/src/model/model.dart';
+import 'package:meta/meta.dart';
 
 /// A [ModelElement] that is a [Container] member.
-mixin ContainerMember on ModelElement implements EnclosedElement {
+mixin ContainerMember on ModelElement {
   /// True if this [ContainerMember] is from an applicable [Extension].
   /// False otherwise, including if this [ContainerMember]'s [enclosingElement]
   /// is the extension it was declared in.
@@ -20,6 +21,9 @@ mixin ContainerMember on ModelElement implements EnclosedElement {
   @override
   Container get enclosingElement;
 
+  /// The container that contains this member.
+  @protected
+  @visibleForTesting
   late final Container definingEnclosingContainer =
       getModelForElement(element.enclosingElement!) as Container;
 
diff --git a/lib/src/model/enclosed_element.dart b/lib/src/model/enclosed_element.dart
deleted file mode 100644
index 9e8666a0c9..0000000000
--- a/lib/src/model/enclosed_element.dart
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-import 'package:dartdoc/src/model/model.dart';
-
-/// An element that is enclosed by some other element.
-///
-/// Libraries are not enclosed.
-abstract class EnclosedElement implements Indexable {
-  ModelElement get enclosingElement;
-}
diff --git a/lib/src/model/extension.dart b/lib/src/model/extension.dart
index e60dfab585..0a124c2fd0 100644
--- a/lib/src/model/extension.dart
+++ b/lib/src/model/extension.dart
@@ -12,7 +12,7 @@ import 'package:meta/meta.dart';
 
 /// Static extension on a given type, containing methods (including getters,
 /// setters, operators).
-class Extension extends Container implements EnclosedElement {
+class Extension extends Container {
   @override
   final ExtensionElement element;
 
diff --git a/lib/src/model/field.dart b/lib/src/model/field.dart
index 833a13647b..27c4a87275 100644
--- a/lib/src/model/field.dart
+++ b/lib/src/model/field.dart
@@ -9,8 +9,7 @@ import 'package:dartdoc/src/model/attribute.dart';
 import 'package:dartdoc/src/model/model.dart';
 
 class Field extends ModelElement
-    with GetterSetterCombo, ContainerMember, Inheritable
-    implements EnclosedElement {
+    with GetterSetterCombo, ContainerMember, Inheritable {
   @override
   final FieldElement element;
 
diff --git a/lib/src/model/inheriting_container.dart b/lib/src/model/inheriting_container.dart
index a756d9974a..39436ec1a6 100644
--- a/lib/src/model/inheriting_container.dart
+++ b/lib/src/model/inheriting_container.dart
@@ -74,8 +74,7 @@ mixin Constructable implements InheritingContainer {
 ///
 /// * **instance**: As with [Container], but also includes inherited children.
 /// * **inherited**: Filtered getters giving only inherited children.
-abstract class InheritingContainer extends Container
-    implements EnclosedElement {
+abstract class InheritingContainer extends Container {
   InheritingContainer(super.library, super.packageGraph);
 
   DefinedElementType? get supertype {
diff --git a/lib/src/model/method.dart b/lib/src/model/method.dart
index 0a8ffb127e..31c337cad4 100644
--- a/lib/src/model/method.dart
+++ b/lib/src/model/method.dart
@@ -12,8 +12,7 @@ import 'package:dartdoc/src/model/comment_referable.dart';
 import 'package:dartdoc/src/model/model.dart';
 
 class Method extends ModelElement
-    with ContainerMember, Inheritable, TypeParameters
-    implements EnclosedElement {
+    with ContainerMember, Inheritable, TypeParameters {
   @override
   final MethodElement element;
 
diff --git a/lib/src/model/model.dart b/lib/src/model/model.dart
index 094b7042fb..07a8f83b94 100644
--- a/lib/src/model/model.dart
+++ b/lib/src/model/model.dart
@@ -15,7 +15,6 @@ export 'documentable.dart';
 export 'documentation.dart';
 export 'documentation_comment.dart';
 export 'dynamic.dart';
-export 'enclosed_element.dart';
 export 'enum.dart';
 export 'extension.dart';
 export 'extension_type.dart';
diff --git a/lib/src/model/model_element.dart b/lib/src/model/model_element.dart
index 881cdef035..52e9da0443 100644
--- a/lib/src/model/model_element.dart
+++ b/lib/src/model/model_element.dart
@@ -338,6 +338,14 @@ abstract class ModelElement extends Canonicalization
     return Accessor(e, library, packageGraph);
   }
 
+  /// The model element enclosing this one.
+  ///
+  /// As some examples:
+  /// * Instances of some subclasses have no enclosing element, like [Library]
+  /// and [Dynamic].
+  /// * A [Container] is enclosed by a [Library].
+  /// * A [Method] is enclosed by a [Container].
+  /// * An [Accessor] is either enclosed by a [Container] or a [Library].
   ModelElement? get enclosingElement;
 
   // Stub for mustache, which would otherwise search enclosing elements to find
diff --git a/lib/src/model/model_function.dart b/lib/src/model/model_function.dart
index deb71f7e05..d1f777bee4 100644
--- a/lib/src/model/model_function.dart
+++ b/lib/src/model/model_function.dart
@@ -32,9 +32,7 @@ class ModelFunctionTypedef extends ModelFunctionTyped {
   String get name => element.enclosingElement!.name!;
 }
 
-class ModelFunctionTyped extends ModelElement
-    with TypeParameters
-    implements EnclosedElement {
+class ModelFunctionTyped extends ModelElement with TypeParameters {
   @override
   final FunctionTypedElement element;
 
diff --git a/lib/src/model/prefix.dart b/lib/src/model/prefix.dart
index 6bea775980..9c4d6d6881 100644
--- a/lib/src/model/prefix.dart
+++ b/lib/src/model/prefix.dart
@@ -11,7 +11,7 @@ import 'package:dartdoc/src/model/model.dart';
 ///
 /// Like [Parameter], it doesn't have doc pages, but participates in lookups.
 /// Forwards to its referenced library if referred to directly.
-class Prefix extends ModelElement with HasNoPage implements EnclosedElement {
+class Prefix extends ModelElement with HasNoPage {
   @override
   final PrefixElement element;
 
diff --git a/lib/src/model/top_level_variable.dart b/lib/src/model/top_level_variable.dart
index 85e19b164d..6d90674bab 100644
--- a/lib/src/model/top_level_variable.dart
+++ b/lib/src/model/top_level_variable.dart
@@ -9,8 +9,7 @@ import 'package:dartdoc/src/model/model.dart';
 
 /// Top-level variables. But also picks up getters and setters?
 class TopLevelVariable extends ModelElement
-    with GetterSetterCombo, Categorization
-    implements EnclosedElement {
+    with GetterSetterCombo, Categorization {
   @override
   final TopLevelVariableElement element;
 
diff --git a/lib/src/model/typedef.dart b/lib/src/model/typedef.dart
index bcafdc185c..899cd59ced 100644
--- a/lib/src/model/typedef.dart
+++ b/lib/src/model/typedef.dart
@@ -9,8 +9,7 @@ import 'package:dartdoc/src/model/comment_referable.dart';
 import 'package:dartdoc/src/model/model.dart';
 
 abstract class Typedef extends ModelElement
-    with TypeParameters, Categorization
-    implements EnclosedElement {
+    with TypeParameters, Categorization {
   @override
   final TypeAliasElement element;