diff --git a/lib/src/model/model_element.dart b/lib/src/model/model_element.dart
index 7b0488648c..e5fcceed01 100644
--- a/lib/src/model/model_element.dart
+++ b/lib/src/model/model_element.dart
@@ -173,8 +173,8 @@ abstract class ModelElement extends Canonicalization
     }
 
     // Return the cached ModelElement if it exists.
-    var cachedModelElement = packageGraph
-        .allConstructedModelElements[(e, library, enclosingContainer)];
+    var cachedModelElement = packageGraph.allConstructedModelElements[
+        ConstructedModelElementsKey(e, library, enclosingContainer)];
     if (cachedModelElement != null) {
       return cachedModelElement;
     }
@@ -263,8 +263,8 @@ abstract class ModelElement extends Canonicalization
     }
 
     // Return the cached ModelElement if it exists.
-    var cachedModelElement = packageGraph
-        .allConstructedModelElements[(e, library, enclosingContainer)];
+    var cachedModelElement = packageGraph.allConstructedModelElements[
+        ConstructedModelElementsKey(e, library, enclosingContainer)];
     if (cachedModelElement != null) {
       return cachedModelElement;
     }
@@ -294,11 +294,12 @@ abstract class ModelElement extends Canonicalization
     //                   is fixed?
     if (library != Library.sentinel && newModelElement is! Parameter) {
       runtimeStats.incrementAccumulator('modelElementCacheInsertion');
-      var key = (e, library, enclosingContainer);
+      var key = ConstructedModelElementsKey(e, library, enclosingContainer);
       library.packageGraph.allConstructedModelElements[key] = newModelElement;
       if (newModelElement is Inheritable) {
         library.packageGraph.allInheritableElements
-            .putIfAbsent((e, library), () => {}).add(newModelElement);
+            .putIfAbsent(InheritableElementsKey(e, library), () => {})
+            .add(newModelElement);
       }
     }
   }
diff --git a/lib/src/model/package_graph.dart b/lib/src/model/package_graph.dart
index 71f7baf73a..4dd0159116 100644
--- a/lib/src/model/package_graph.dart
+++ b/lib/src/model/package_graph.dart
@@ -318,11 +318,12 @@ class PackageGraph with CommentReferable, Nameable, ModelBuilder {
 
   /// All [ModelElement]s constructed for this package; a superset of
   /// the elements gathered in [_gatherModelElements].
-  final Map<(Element element, Library library, Container? enclosingElement),
-      ModelElement> allConstructedModelElements = {};
+  final Map<ConstructedModelElementsKey, ModelElement>
+      allConstructedModelElements = {};
 
   /// Anything that might be inheritable, place here for later lookup.
-  final Map<(Element, Library), Set<ModelElement>> allInheritableElements = {};
+  final Map<InheritableElementsKey, Set<ModelElement>> allInheritableElements =
+      {};
 
   /// A mapping of the list of classes which implement each class.
   final Map<InheritingContainer, List<InheritingContainer>> _implementors =
@@ -800,18 +801,20 @@ class PackageGraph with CommentReferable, Nameable, ModelBuilder {
       {InheritingContainer? preferredClass}) {
     var candidates = <ModelElement>{};
     if (lib != null) {
-      var constructedWithKey = allConstructedModelElements[(e, lib, null)];
+      var constructedWithKey = allConstructedModelElements[
+          ConstructedModelElementsKey(e, lib, null)];
       if (constructedWithKey != null) {
         candidates.add(constructedWithKey);
       }
-      var constructedWithKeyWithClass =
-          allConstructedModelElements[(e, lib, preferredClass)];
+      var constructedWithKeyWithClass = allConstructedModelElements[
+          ConstructedModelElementsKey(e, lib, preferredClass)];
       if (constructedWithKeyWithClass != null) {
         candidates.add(constructedWithKeyWithClass);
       }
       if (candidates.isEmpty) {
         candidates = {
-          ...?allInheritableElements[(e, lib)]?.where((me) => me.isCanonical),
+          ...?allInheritableElements[InheritableElementsKey(e, lib)]
+              ?.where((me) => me.isCanonical),
         };
       }
     }
@@ -1004,3 +1007,30 @@ class PackageGraph with CommentReferable, Nameable, ModelBuilder {
   @override
   Iterable<CommentReferable> get referenceParents => const [];
 }
+
+class ConstructedModelElementsKey {
+  final Element element;
+  final Library library;
+  final Container? enclosingElement;
+
+  ConstructedModelElementsKey(
+      this.element, this.library, this.enclosingElement);
+
+  @override
+  late final int hashCode = Object.hash(element, library, enclosingElement);
+
+  @override
+  bool operator ==(Object other) {
+    if (other is! ConstructedModelElementsKey) return false;
+    return other.element == element &&
+        other.library == library &&
+        other.enclosingElement == enclosingElement;
+  }
+}
+
+class InheritableElementsKey {
+  final Element element;
+  final Library library;
+
+  InheritableElementsKey(this.element, this.library);
+}