diff --git a/DEPS b/DEPS
index a567d7f..7bb539d 100644
--- a/DEPS
+++ b/DEPS
@@ -44,7 +44,7 @@
   # co19 is a cipd package. Use update.sh in tests/co19[_2] to update these
   # hashes. It requires access to the dart-build-access group, which EngProd
   # has.
-  "co19_rev": "e9f3b0239dedd349084ca1e0b9d2ceacf4b2a1ef",
+  "co19_rev": "3f7916727cf025bdedbe2b49625a8c403bead66b",
   # This line prevents conflicts when both packages are rolled simultaneously.
   "co19_2_rev": "13344ad01472df9badfa78fd6aa411f042e13354",
 
diff --git a/pkg/front_end/lib/src/fasta/builder/constructor_builder.dart b/pkg/front_end/lib/src/fasta/builder/constructor_builder.dart
index cf6125b..c71dda4 100644
--- a/pkg/front_end/lib/src/fasta/builder/constructor_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/constructor_builder.dart
@@ -126,19 +126,24 @@
       int charOffset,
       this.charOpenParenOffset,
       int charEndOffset,
-      Member? referenceFrom,
+      Reference? constructorReference,
+      Reference? tearOffReference,
       {String? nativeMethodName,
       required bool forAbstractClassOrEnum})
       : _constructor = new Constructor(new FunctionNode(null),
             name: new Name(name, compilationUnit.library),
             fileUri: compilationUnit.fileUri,
-            reference: referenceFrom?.reference)
+            reference: constructorReference)
           ..startFileOffset = startCharOffset
           ..fileOffset = charOffset
           ..fileEndOffset = charEndOffset
           ..isNonNullableByDefault = compilationUnit.isNonNullableByDefault,
         _constructorTearOff = createConstructorTearOffProcedure(
-            name, compilationUnit, compilationUnit.fileUri, charOffset,
+            name,
+            compilationUnit,
+            compilationUnit.fileUri,
+            charOffset,
+            tearOffReference,
             forAbstractClassOrEnum: forAbstractClassOrEnum),
         super(metadata, modifiers, returnType, name, typeVariables, formals,
             compilationUnit, charOffset, nativeMethodName);
diff --git a/pkg/front_end/lib/src/fasta/builder/enum_builder.dart b/pkg/front_end/lib/src/fasta/builder/enum_builder.dart
index 6f9fcec..0b293c4 100644
--- a/pkg/front_end/lib/src/fasta/builder/enum_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/enum_builder.dart
@@ -40,6 +40,7 @@
         templateDuplicatedDeclarationSyntheticCause,
         templateEnumConstantSameNameAsEnclosing;
 
+import '../kernel/constructor_tearoff_lowering.dart';
 import '../kernel/kernel_helper.dart';
 
 import '../util/helpers.dart';
@@ -198,14 +199,17 @@
             ? referencesFromIndexed.library.reference
             : parent.library.reference);
 
-    Constructor? constructorReference;
+    Reference? constructorReference;
+    Reference? tearOffReference;
     Reference? toStringReference;
     Reference? valuesFieldReference;
     Reference? valuesGetterReference;
     Reference? valuesSetterReference;
     if (referencesFromIndexed != null) {
       constructorReference =
-          referencesFromIndexed.lookupConstructor(new Name("")) as Constructor;
+          referencesFromIndexed.lookupConstructorReference(new Name(""));
+      tearOffReference = referencesFromIndexed.lookupGetterReference(
+          constructorTearOffName("", referencesFromIndexed.library));
       toStringReference =
           referencesFromIndexed.lookupGetterReference(new Name("toString"));
       Name valuesName = new Name("values");
@@ -235,6 +239,7 @@
         charOffset,
         charEndOffset,
         constructorReference,
+        tearOffReference,
         forAbstractClassOrEnum: true);
     constructors[""] = constructorBuilder;
     FieldBuilder valuesBuilder = new SourceFieldBuilder(
diff --git a/pkg/front_end/lib/src/fasta/builder/factory_builder.dart b/pkg/front_end/lib/src/fasta/builder/factory_builder.dart
index 2561223..5db68f5 100644
--- a/pkg/front_end/lib/src/fasta/builder/factory_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/factory_builder.dart
@@ -66,6 +66,7 @@
       this.charOpenParenOffset,
       int charEndOffset,
       Reference? procedureReference,
+      Reference? tearOffReference,
       AsyncMarker asyncModifier,
       NameScheme nameScheme,
       {String? nativeMethodName})
@@ -79,8 +80,8 @@
           ..fileOffset = charOffset
           ..fileEndOffset = charEndOffset
           ..isNonNullableByDefault = libraryBuilder.isNonNullableByDefault,
-        _factoryTearOff = createFactoryTearOffProcedure(
-            name, libraryBuilder, libraryBuilder.fileUri, charOffset),
+        _factoryTearOff = createFactoryTearOffProcedure(name, libraryBuilder,
+            libraryBuilder.fileUri, charOffset, tearOffReference),
         super(metadata, modifiers, returnType, name, typeVariables, formals,
             libraryBuilder, charOffset, nativeMethodName) {
     this.asyncModifier = asyncModifier;
@@ -273,6 +274,7 @@
       int charOpenParenOffset,
       int charEndOffset,
       Reference? procedureReference,
+      Reference? tearOffReference,
       NameScheme nameScheme,
       String? nativeMethodName,
       this.redirectionTarget)
@@ -289,6 +291,7 @@
             charOpenParenOffset,
             charEndOffset,
             procedureReference,
+            tearOffReference,
             AsyncMarker.Sync,
             nameScheme,
             nativeMethodName: nativeMethodName);
diff --git a/pkg/front_end/lib/src/fasta/kernel/constructor_tearoff_lowering.dart b/pkg/front_end/lib/src/fasta/kernel/constructor_tearoff_lowering.dart
index d931f8e..e3dd8b1 100644
--- a/pkg/front_end/lib/src/fasta/kernel/constructor_tearoff_lowering.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/constructor_tearoff_lowering.dart
@@ -97,8 +97,12 @@
 /// the given [name] in [compilationUnit].
 ///
 /// If constructor tear off lowering is not enabled, `null` is returned.
-Procedure? createConstructorTearOffProcedure(String name,
-    SourceLibraryBuilder compilationUnit, Uri fileUri, int fileOffset,
+Procedure? createConstructorTearOffProcedure(
+    String name,
+    SourceLibraryBuilder compilationUnit,
+    Uri fileUri,
+    int fileOffset,
+    Reference? reference,
     {required bool forAbstractClassOrEnum}) {
   if (!forAbstractClassOrEnum &&
       compilationUnit
@@ -107,7 +111,8 @@
         compilationUnit,
         constructorTearOffName(name, compilationUnit.library),
         fileUri,
-        fileOffset);
+        fileOffset,
+        reference);
   }
   return null;
 }
@@ -116,15 +121,20 @@
 /// the given [name] in [compilationUnit].
 ///
 /// If constructor tear off lowering is not enabled, `null` is returned.
-Procedure? createFactoryTearOffProcedure(String name,
-    SourceLibraryBuilder compilationUnit, Uri fileUri, int fileOffset) {
+Procedure? createFactoryTearOffProcedure(
+    String name,
+    SourceLibraryBuilder compilationUnit,
+    Uri fileUri,
+    int fileOffset,
+    Reference? reference) {
   if (compilationUnit
       .loader.target.backendTarget.isFactoryTearOffLoweringEnabled) {
     return _createTearOffProcedure(
         compilationUnit,
         constructorTearOffName(name, compilationUnit.library),
         fileUri,
-        fileOffset);
+        fileOffset,
+        reference);
   }
   return null;
 }
@@ -132,13 +142,19 @@
 /// Creates the [Procedure] for the lowering of a typedef tearoff of a
 /// constructor of the given [name] in with the typedef defined in
 /// [libraryBuilder].
-Procedure createTypedefTearOffProcedure(String typedefName, String name,
-    SourceLibraryBuilder libraryBuilder, Uri fileUri, int fileOffset) {
+Procedure createTypedefTearOffProcedure(
+    String typedefName,
+    String name,
+    SourceLibraryBuilder libraryBuilder,
+    Uri fileUri,
+    int fileOffset,
+    Reference? reference) {
   return _createTearOffProcedure(
       libraryBuilder,
       typedefTearOffName(typedefName, name, libraryBuilder.library),
       fileUri,
-      fileOffset);
+      fileOffset,
+      reference);
 }
 
 /// Creates the parameters and body for [tearOff] based on [constructor] in
@@ -307,9 +323,9 @@
 /// Creates the synthesized [Procedure] node for a tear off lowering by the
 /// given [name].
 Procedure _createTearOffProcedure(SourceLibraryBuilder libraryBuilder,
-    Name name, Uri fileUri, int fileOffset) {
+    Name name, Uri fileUri, int fileOffset, Reference? reference) {
   return new Procedure(name, ProcedureKind.Method, new FunctionNode(null),
-      fileUri: fileUri, isStatic: true)
+      fileUri: fileUri, isStatic: true, reference: reference)
     ..startFileOffset = fileOffset
     ..fileOffset = fileOffset
     ..fileEndOffset = fileOffset
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
index 1600030..91a86f3 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_target.dart
@@ -773,10 +773,13 @@
     }
 
     IndexedClass? indexedClass = builder.referencesFromIndexed;
-    Constructor? referenceFrom;
+    Reference? constructorReference;
+    Reference? tearOffReference;
     if (indexedClass != null) {
-      referenceFrom =
-          indexedClass.lookupConstructor(new Name("")) as Constructor?;
+      constructorReference =
+          indexedClass.lookupConstructorReference(new Name(""));
+      tearOffReference = indexedClass.lookupGetterReference(
+          constructorTearOffName("", indexedClass.library));
     }
 
     /// From [Dart Programming Language Specification, 4th Edition](
@@ -784,8 +787,8 @@
     /// >Iff no constructor is specified for a class C, it implicitly has a
     /// >default constructor C() : super() {}, unless C is class Object.
     // The superinitializer is installed below in [finishConstructors].
-    builder.addSyntheticConstructor(
-        _makeDefaultConstructor(builder, referenceFrom));
+    builder.addSyntheticConstructor(_makeDefaultConstructor(
+        builder, constructorReference, tearOffReference));
   }
 
   void installForwardingConstructors(SourceClassBuilder builder) {
@@ -828,10 +831,13 @@
     }
 
     IndexedClass? indexedClass = builder.referencesFromIndexed;
-    Constructor? referenceFrom;
+    Reference? constructorReference;
+    Reference? tearOffReference;
     if (indexedClass != null) {
-      referenceFrom =
-          indexedClass.lookupConstructor(new Name("")) as Constructor?;
+      constructorReference =
+          indexedClass.lookupConstructorReference(new Name(""));
+      tearOffReference = indexedClass.lookupGetterReference(
+          constructorTearOffName("", indexedClass.library));
     }
 
     if (supertype is ClassBuilder) {
@@ -842,14 +848,21 @@
       void addSyntheticConstructor(String name, MemberBuilder memberBuilder) {
         if (memberBuilder.member is Constructor) {
           substitutionMap ??= builder.getSubstitutionMap(superclassBuilder.cls);
-          Constructor? referenceFrom = indexedClass?.lookupConstructor(
-              new Name(name, indexedClass.library)) as Constructor?;
+          Reference? constructorReference;
+          Reference? tearOffReference;
+          if (indexedClass != null) {
+            constructorReference = indexedClass.lookupConstructorReference(
+                new Name(name, indexedClass.library));
+            tearOffReference = indexedClass.lookupGetterReference(
+                constructorTearOffName(name, indexedClass.library));
+          }
           builder.addSyntheticConstructor(_makeMixinApplicationConstructor(
               builder,
               builder.cls.mixin,
               memberBuilder as MemberBuilderImpl,
               substitutionMap!,
-              referenceFrom));
+              constructorReference,
+              tearOffReference));
           isConstructorAdded = true;
         }
       }
@@ -858,16 +871,16 @@
           includeInjectedConstructors: true);
 
       if (!isConstructorAdded) {
-        builder.addSyntheticConstructor(
-            _makeDefaultConstructor(builder, referenceFrom));
+        builder.addSyntheticConstructor(_makeDefaultConstructor(
+            builder, constructorReference, tearOffReference));
       }
     } else if (supertype is InvalidTypeDeclarationBuilder ||
         supertype is TypeVariableBuilder ||
         supertype is DynamicTypeDeclarationBuilder ||
         supertype is VoidTypeDeclarationBuilder ||
         supertype is NeverTypeDeclarationBuilder) {
-      builder.addSyntheticConstructor(
-          _makeDefaultConstructor(builder, referenceFrom));
+      builder.addSyntheticConstructor(_makeDefaultConstructor(
+          builder, constructorReference, tearOffReference));
     } else {
       unhandled("${supertype.runtimeType}", "installForwardingConstructors",
           builder.charOffset, builder.fileUri);
@@ -879,7 +892,8 @@
       Class mixin,
       MemberBuilderImpl superConstructorBuilder,
       Map<TypeParameter, DartType> substitutionMap,
-      Constructor? referenceFrom) {
+      Reference? constructorReference,
+      Reference? tearOffReference) {
     bool hasTypeDependency = false;
     Substitution substitution = Substitution.fromMap(substitutionMap);
 
@@ -950,7 +964,7 @@
         initializers: <Initializer>[initializer],
         isSynthetic: true,
         isConst: isConst,
-        reference: referenceFrom?.reference,
+        reference: constructorReference,
         fileUri: cls.fileUri)
       // TODO(johnniwinther): Should we add file offsets to synthesized
       //  constructors?
@@ -970,6 +984,7 @@
         classBuilder.library,
         cls.fileUri,
         cls.fileOffset,
+        tearOffReference,
         forAbstractClassOrEnum: classBuilder.isAbstract);
 
     if (constructorTearOff != null) {
@@ -996,14 +1011,16 @@
   }
 
   SyntheticConstructorBuilder _makeDefaultConstructor(
-      SourceClassBuilder classBuilder, Constructor? referenceFrom) {
+      SourceClassBuilder classBuilder,
+      Reference? constructorReference,
+      Reference? tearOffReference) {
     Class enclosingClass = classBuilder.cls;
     Constructor constructor = new Constructor(
         new FunctionNode(new EmptyStatement(),
             returnType: makeConstructorReturnType(enclosingClass)),
         name: new Name(""),
         isSynthetic: true,
-        reference: referenceFrom?.reference,
+        reference: constructorReference,
         fileUri: enclosingClass.fileUri)
       ..fileOffset = enclosingClass.fileOffset
       // TODO(johnniwinther): Should we add file end offsets to synthesized
@@ -1011,8 +1028,12 @@
       //..fileEndOffset = enclosingClass.fileOffset
       ..isNonNullableByDefault =
           enclosingClass.enclosingLibrary.isNonNullableByDefault;
-    Procedure? constructorTearOff = createConstructorTearOffProcedure('',
-        classBuilder.library, enclosingClass.fileUri, enclosingClass.fileOffset,
+    Procedure? constructorTearOff = createConstructorTearOffProcedure(
+        '',
+        classBuilder.library,
+        enclosingClass.fileUri,
+        enclosingClass.fileOffset,
+        tearOffReference,
         forAbstractClassOrEnum:
             enclosingClass.isAbstract || enclosingClass.isEnum);
     if (constructorTearOff != null) {
diff --git a/pkg/front_end/lib/src/fasta/source/source_library_builder.dart b/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
index b046570..f1cb153 100644
--- a/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_library_builder.dart
@@ -82,6 +82,7 @@
 import '../import.dart' show Import;
 
 import '../kernel/class_hierarchy_builder.dart';
+import '../kernel/constructor_tearoff_lowering.dart';
 import '../kernel/implicit_field_type.dart';
 import '../kernel/internal_ast.dart';
 import '../kernel/load_library_builder.dart';
@@ -2352,10 +2353,14 @@
       String? nativeMethodName,
       {Token? beginInitializers,
       required bool forAbstractClass}) {
-    Member? referenceFrom;
+    Reference? constructorReference;
+    Reference? tearOffReference;
     if (_currentClassReferencesFromIndexed != null) {
-      referenceFrom = _currentClassReferencesFromIndexed!.lookupConstructor(
-          new Name(
+      constructorReference = _currentClassReferencesFromIndexed!
+          .lookupConstructorReference(new Name(
+              constructorName, _currentClassReferencesFromIndexed!.library));
+      tearOffReference = _currentClassReferencesFromIndexed!
+          .lookupGetterReference(constructorTearOffName(
               constructorName, _currentClassReferencesFromIndexed!.library));
     }
     ConstructorBuilder constructorBuilder = new SourceConstructorBuilder(
@@ -2370,12 +2375,14 @@
         charOffset,
         charOpenParenOffset,
         charEndOffset,
-        referenceFrom,
+        constructorReference,
+        tearOffReference,
         nativeMethodName: nativeMethodName,
         forAbstractClassOrEnum: forAbstractClass);
     checkTypeVariables(typeVariables, constructorBuilder);
+    // TODO(johnniwinther): There is no way to pass the tear off reference here.
     addBuilder(constructorName, constructorBuilder, charOffset,
-        getterReference: referenceFrom?.reference);
+        getterReference: constructorReference);
     if (nativeMethodName != null) {
       addNativeMethod(constructorBuilder);
     }
@@ -2538,10 +2545,16 @@
                 .reference
             : library.reference);
 
-    Reference? reference = _currentClassReferencesFromIndexed
-        ?.lookupConstructor(new Name(
-            procedureName, _currentClassReferencesFromIndexed!.library))
-        ?.reference;
+    Reference? constructorReference;
+    Reference? tearOffReference;
+    if (_currentClassReferencesFromIndexed != null) {
+      constructorReference = _currentClassReferencesFromIndexed!
+          .lookupConstructorReference(new Name(
+              procedureName, _currentClassReferencesFromIndexed!.library));
+      tearOffReference = _currentClassReferencesFromIndexed!
+          .lookupGetterReference(constructorTearOffName(
+              procedureName, _currentClassReferencesFromIndexed!.library));
+    }
 
     SourceFactoryBuilder procedureBuilder;
     if (redirectionTarget != null) {
@@ -2560,7 +2573,8 @@
           charOffset,
           charOpenParenOffset,
           charEndOffset,
-          reference,
+          constructorReference,
+          tearOffReference,
           procedureNameScheme,
           nativeMethodName,
           redirectionTarget);
@@ -2580,7 +2594,8 @@
           charOffset,
           charOpenParenOffset,
           charEndOffset,
-          reference,
+          constructorReference,
+          tearOffReference,
           asyncModifier,
           procedureNameScheme,
           nativeMethodName: nativeMethodName);
@@ -2598,7 +2613,7 @@
 
     factoryDeclaration.resolveTypes(procedureBuilder.typeVariables, this);
     addBuilder(procedureName, procedureBuilder, charOffset,
-        getterReference: reference);
+        getterReference: constructorReference);
     if (nativeMethodName != null) {
       addNativeMethod(procedureBuilder);
     }
diff --git a/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart b/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
index bde992e..ea9bb01 100644
--- a/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_type_alias_builder.dart
@@ -320,9 +320,16 @@
           }
           Name targetName =
               new Name(constructorName, declaration.library.library);
+          Reference? tearOffReference;
+          if (library.referencesFromIndexed != null) {
+            tearOffReference = library.referencesFromIndexed!
+                .lookupGetterReference(typedefTearOffName(name, constructorName,
+                    library.referencesFromIndexed!.library));
+          }
+
           Procedure tearOff = tearOffs![targetName] =
               createTypedefTearOffProcedure(name, constructorName, library,
-                  target.fileUri, target.fileOffset);
+                  target.fileUri, target.fileOffset, tearOffReference);
           _tearOffDependencies![tearOff] = target;
 
           buildTypedefTearOffProcedure(tearOff, target, declaration.cls,
diff --git a/pkg/front_end/test/fasta/testing/suite.dart b/pkg/front_end/test/fasta/testing/suite.dart
index 4275910..2cda1e4 100644
--- a/pkg/front_end/test/fasta/testing/suite.dart
+++ b/pkg/front_end/test/fasta/testing/suite.dart
@@ -73,6 +73,8 @@
 import 'package:front_end/src/fasta/kernel/kernel_target.dart'
     show KernelTarget;
 
+import 'package:front_end/src/fasta/kernel/utils.dart' show ByteSink;
+
 import 'package:front_end/src/fasta/messages.dart' show LocatedMessage;
 
 import 'package:front_end/src/fasta/ticker.dart' show Ticker;
@@ -108,6 +110,8 @@
         Visitor,
         VisitorVoidMixin;
 
+import 'package:kernel/binary/ast_to_binary.dart' show BinaryPrinter;
+
 import 'package:kernel/class_hierarchy.dart' show ClassHierarchy;
 
 import 'package:kernel/core_types.dart' show CoreTypes;
@@ -1114,6 +1118,7 @@
       ..experimentEnabledVersionForTesting = experimentEnabledVersion
       ..experimentReleasedVersionForTesting = experimentReleasedVersion
       ..skipPlatformVerification = true
+      ..omitPlatform = true
       ..target = createTarget(folderOptions, context);
     if (folderOptions.overwriteCurrentSdkVersion != null) {
       compilerOptions.currentSdkVersion =
@@ -1204,6 +1209,10 @@
         new IncrementalCompiler.fromComponent(
             new CompilerContext(compilationSetup.options), platform);
     final Component component = await incrementalCompiler.computeDelta();
+    if (!canSerialize(component)) {
+      return new Result<ComponentResult>(result, semiFuzzFailure,
+          "Couldn't serialize initial component for fuzzing");
+    }
 
     final Set<Uri> userLibraries =
         createUserLibrariesImportUriSet(component, uriTranslator);
@@ -1231,6 +1240,10 @@
       incrementalCompiler.invalidate(importUri);
       final Component newComponent =
           await incrementalCompiler.computeDelta(fullComponent: true);
+      if (!canSerialize(newComponent)) {
+        return new Result<ComponentResult>(
+            result, semiFuzzFailure, "Couldn't serialize fuzzed component");
+      }
 
       final Set<Uri> newUserLibraries =
           createUserLibrariesImportUriSet(newComponent, uriTranslator);
@@ -1285,6 +1298,17 @@
     return null;
   }
 
+  bool canSerialize(Component component) {
+    ByteSink byteSink = new ByteSink();
+    try {
+      new BinaryPrinter(byteSink).writeComponentFile(component);
+      return true;
+    } catch (e, st) {
+      print("Can't serialize, got '$e' from $st");
+      return false;
+    }
+  }
+
   /// Perform a number of compilations where each user-file is in turn sorted
   /// in both ascending and descending order (i.e. the procedures and classes
   /// etc are sorted).
@@ -1306,7 +1330,11 @@
     IncrementalCompiler incrementalCompiler =
         new IncrementalCompiler.fromComponent(
             new CompilerContext(compilationSetup.options), platform);
-    await incrementalCompiler.computeDelta();
+    Component initialComponent = await incrementalCompiler.computeDelta();
+    if (!canSerialize(initialComponent)) {
+      return new Result<ComponentResult>(result, semiFuzzFailure,
+          "Couldn't serialize initial component for fuzzing");
+    }
 
     final bool expectErrors = compilationSetup.errors.isNotEmpty;
     List<Iterable<String>> originalErrors =
@@ -1365,7 +1393,11 @@
         incrementalCompiler = new IncrementalCompiler.fromComponent(
             new CompilerContext(compilationSetup.options), platform);
         try {
-          await incrementalCompiler.computeDelta();
+          Component component = await incrementalCompiler.computeDelta();
+          if (!canSerialize(component)) {
+            return new Result<ComponentResult>(
+                result, semiFuzzFailure, "Couldn't serialize fuzzed component");
+          }
         } catch (e, st) {
           return new Result<ComponentResult>(
               result,
diff --git a/pkg/front_end/test/spell_checking_list_tests.txt b/pkg/front_end/test/spell_checking_list_tests.txt
index 82edba1..6beac94 100644
--- a/pkg/front_end/test/spell_checking_list_tests.txt
+++ b/pkg/front_end/test/spell_checking_list_tests.txt
@@ -459,6 +459,7 @@
 futu
 futures
 fuzz
+fuzzed
 fuzzing
 fx
 g1a
diff --git a/pkg/front_end/testcases/incremental/constructor_change.yaml b/pkg/front_end/testcases/incremental/constructor_change.yaml
new file mode 100644
index 0000000..58e4c05
--- /dev/null
+++ b/pkg/front_end/testcases/incremental/constructor_change.yaml
@@ -0,0 +1,79 @@
+# Copyright (c) 2021, 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.md file.
+
+# Compile an application, change a file, but don't change the outline.
+# Try to mess up the hierarchy.
+
+type: newworld
+target: DDC
+worlds:
+  - entry: main.dart
+    experiments: alternative-invalidation-strategy
+    sources:
+      main.dart: |
+        import "lib1.dart";
+        import "lib2.dart";
+        import "lib3.dart";
+
+        main() {
+          Foo foo = new Bar();
+          lib3Method(foo);
+        }
+      lib1.dart: |
+        class Foo {
+          void fooMethod() {
+            // Not filled out.
+          }
+        }
+      lib2.dart: |
+        import "lib1.dart";
+        class Bar extends Foo {
+          void barMethod() {
+            // Not filled out.
+          }
+        }
+      lib3.dart: |
+        import "lib1.dart";
+        import "lib2.dart";
+        void lib3Method(Foo foo) {
+          var f = Bar.new;
+          Foo bar = f();
+          bool equal = foo == bar;
+          print("foo == bar = $equal");
+        }
+    expectedLibraryCount: 4
+  - entry: main.dart
+    experiments: alternative-invalidation-strategy
+    worldType: updated
+    expectInitializeFromDill: false
+    invalidate:
+      - lib1.dart
+    sources:
+      lib1.dart: |
+        class Foo {
+          void fooMethod() {
+            print("fooMethod");
+          }
+        }
+    expectedLibraryCount: 4
+    expectsRebuildBodiesOnly: true
+  - entry: main.dart
+    experiments: alternative-invalidation-strategy
+    worldType: updated
+    expectInitializeFromDill: false
+    invalidate:
+      - lib3.dart
+    sources:
+      lib3.dart: |
+        import "lib1.dart";
+        import "lib2.dart";
+        void lib3Method(Foo foo) {
+          var f = Bar.new;
+          Foo bar = f();
+          bool equal = foo == bar;
+          print("foo == bar = $equal");
+          print("Done!");
+        }
+    expectedLibraryCount: 4
+    expectsRebuildBodiesOnly: true
diff --git a/pkg/front_end/testcases/incremental/constructor_change.yaml.world.1.expect b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.1.expect
new file mode 100644
index 0000000..3885ee0
--- /dev/null
+++ b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.1.expect
@@ -0,0 +1,51 @@
+main = main::main;
+library from "org-dartlang-test:///lib1.dart" as lib1 {
+
+  class Foo extends dart.core::Object {
+    synthetic constructor •() → lib1::Foo
+      : super dart.core::Object::•()
+      ;
+    method fooMethod() → void {}
+    static method _#new#tearOff() → lib1::Foo
+      return new lib1::Foo::•();
+  }
+}
+library from "org-dartlang-test:///lib2.dart" as lib2 {
+
+  import "org-dartlang-test:///lib1.dart";
+
+  class Bar extends lib1::Foo {
+    synthetic constructor •() → lib2::Bar
+      : super lib1::Foo::•()
+      ;
+    method barMethod() → void {}
+    static method _#new#tearOff() → lib2::Bar
+      return new lib2::Bar::•();
+  }
+}
+library from "org-dartlang-test:///lib3.dart" as lib3 {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+
+  static method lib3Method(lib1::Foo foo) → void {
+    () → lib2::Bar f = #C1;
+    lib1::Foo bar = f(){() → lib2::Bar};
+    dart.core::bool equal = foo =={dart.core::Object::==}{(dart.core::Object) → dart.core::bool} bar;
+    dart.core::print("foo == bar = ${equal}");
+  }
+}
+library from "org-dartlang-test:///main.dart" as main {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+  import "org-dartlang-test:///lib3.dart";
+
+  static method main() → dynamic {
+    lib1::Foo foo = new lib2::Bar::•();
+    lib3::lib3Method(foo);
+  }
+}
+constants  {
+  #C1 = static-tearoff lib2::Bar::_#new#tearOff
+}
diff --git a/pkg/front_end/testcases/incremental/constructor_change.yaml.world.2.expect b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.2.expect
new file mode 100644
index 0000000..8b4f83e
--- /dev/null
+++ b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.2.expect
@@ -0,0 +1,53 @@
+main = main::main;
+library from "org-dartlang-test:///lib1.dart" as lib1 {
+
+  class Foo extends dart.core::Object {
+    synthetic constructor •() → lib1::Foo
+      : super dart.core::Object::•()
+      ;
+    method fooMethod() → void {
+      dart.core::print("fooMethod");
+    }
+    static method _#new#tearOff() → lib1::Foo
+      return new lib1::Foo::•();
+  }
+}
+library from "org-dartlang-test:///lib2.dart" as lib2 {
+
+  import "org-dartlang-test:///lib1.dart";
+
+  class Bar extends lib1::Foo {
+    synthetic constructor •() → lib2::Bar
+      : super lib1::Foo::•()
+      ;
+    method barMethod() → void {}
+    static method _#new#tearOff() → lib2::Bar
+      return new lib2::Bar::•();
+  }
+}
+library from "org-dartlang-test:///lib3.dart" as lib3 {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+
+  static method lib3Method(lib1::Foo foo) → void {
+    () → lib2::Bar f = #C1;
+    lib1::Foo bar = f(){() → lib2::Bar};
+    dart.core::bool equal = foo =={dart.core::Object::==}{(dart.core::Object) → dart.core::bool} bar;
+    dart.core::print("foo == bar = ${equal}");
+  }
+}
+library from "org-dartlang-test:///main.dart" as main {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+  import "org-dartlang-test:///lib3.dart";
+
+  static method main() → dynamic {
+    lib1::Foo foo = new lib2::Bar::•();
+    lib3::lib3Method(foo);
+  }
+}
+constants  {
+  #C1 = static-tearoff lib2::Bar::_#new#tearOff
+}
diff --git a/pkg/front_end/testcases/incremental/constructor_change.yaml.world.3.expect b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.3.expect
new file mode 100644
index 0000000..3436a8d
--- /dev/null
+++ b/pkg/front_end/testcases/incremental/constructor_change.yaml.world.3.expect
@@ -0,0 +1,54 @@
+main = main::main;
+library from "org-dartlang-test:///lib1.dart" as lib1 {
+
+  class Foo extends dart.core::Object {
+    synthetic constructor •() → lib1::Foo
+      : super dart.core::Object::•()
+      ;
+    method fooMethod() → void {
+      dart.core::print("fooMethod");
+    }
+    static method _#new#tearOff() → lib1::Foo
+      return new lib1::Foo::•();
+  }
+}
+library from "org-dartlang-test:///lib2.dart" as lib2 {
+
+  import "org-dartlang-test:///lib1.dart";
+
+  class Bar extends lib1::Foo {
+    synthetic constructor •() → lib2::Bar
+      : super lib1::Foo::•()
+      ;
+    method barMethod() → void {}
+    static method _#new#tearOff() → lib2::Bar
+      return new lib2::Bar::•();
+  }
+}
+library from "org-dartlang-test:///lib3.dart" as lib3 {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+
+  static method lib3Method(lib1::Foo foo) → void {
+    () → lib2::Bar f = #C1;
+    lib1::Foo bar = f(){() → lib2::Bar};
+    dart.core::bool equal = foo =={dart.core::Object::==}{(dart.core::Object) → dart.core::bool} bar;
+    dart.core::print("foo == bar = ${equal}");
+    dart.core::print("Done!");
+  }
+}
+library from "org-dartlang-test:///main.dart" as main {
+
+  import "org-dartlang-test:///lib1.dart";
+  import "org-dartlang-test:///lib2.dart";
+  import "org-dartlang-test:///lib3.dart";
+
+  static method main() → dynamic {
+    lib1::Foo foo = new lib2::Bar::•();
+    lib3::lib3Method(foo);
+  }
+}
+constants  {
+  #C1 = static-tearoff lib2::Bar::_#new#tearOff
+}
diff --git a/pkg/kernel/lib/reference_from_index.dart b/pkg/kernel/lib/reference_from_index.dart
index 6182a4b..47c7260 100644
--- a/pkg/kernel/lib/reference_from_index.dart
+++ b/pkg/kernel/lib/reference_from_index.dart
@@ -9,7 +9,6 @@
         Extension,
         Field,
         Library,
-        Member,
         Name,
         Procedure,
         ProcedureKind,
@@ -116,19 +115,19 @@
 
 class IndexedClass extends IndexedContainer {
   final Class cls;
-  final Map<Name, Member> _constructors = new Map<Name, Member>();
+  final Map<Name, Reference> _constructors = new Map<Name, Reference>();
   @override
   final Library library;
 
   IndexedClass._(this.cls, this.library) {
     for (int i = 0; i < cls.constructors.length; i++) {
       Constructor constructor = cls.constructors[i];
-      _constructors[constructor.name] = constructor;
+      _constructors[constructor.name] = constructor.reference;
     }
     for (int i = 0; i < cls.procedures.length; i++) {
       Procedure procedure = cls.procedures[i];
       if (procedure.isFactory) {
-        _constructors[procedure.name] = procedure;
+        _constructors[procedure.name] = procedure.reference;
       } else {
         _addProcedure(procedure);
       }
@@ -136,5 +135,5 @@
     _addFields(cls.fields);
   }
 
-  Member? lookupConstructor(Name name) => _constructors[name];
+  Reference? lookupConstructorReference(Name name) => _constructors[name];
 }
diff --git a/pkg/vm/lib/transformations/ffi_definitions.dart b/pkg/vm/lib/transformations/ffi_definitions.dart
index b0aa9a5..29b58fc 100644
--- a/pkg/vm/lib/transformations/ffi_definitions.dart
+++ b/pkg/vm/lib/transformations/ffi_definitions.dart
@@ -526,7 +526,7 @@
         "#typedDataBase",
         type: coreTypes.objectNonNullableRawType);
     final name = Name("#fromTypedDataBase");
-    final referenceFrom = indexedClass?.lookupConstructor(name);
+    final reference = indexedClass?.lookupConstructorReference(name);
     final Constructor ctor = Constructor(
         FunctionNode(EmptyStatement(),
             positionalParameters: [typedDataBase],
@@ -540,7 +540,7 @@
               Arguments([VariableGet(typedDataBase)]))
         ],
         fileUri: node.fileUri,
-        reference: referenceFrom?.reference)
+        reference: reference)
       ..fileOffset = node.fileOffset
       ..isNonNullableByDefault = node.enclosingLibrary.isNonNullableByDefault;
 
diff --git a/tools/VERSION b/tools/VERSION
index 438cf7b..ca28cda 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -27,5 +27,5 @@
 MAJOR 2
 MINOR 15
 PATCH 0
-PRERELEASE 182
+PRERELEASE 183
 PRERELEASE_PATCH 0
\ No newline at end of file