diff --git a/protobuf/lib/src/protobuf/builder_info.dart b/protobuf/lib/src/protobuf/builder_info.dart
index 1ae34413..375fe0d6 100644
--- a/protobuf/lib/src/protobuf/builder_info.dart
+++ b/protobuf/lib/src/protobuf/builder_info.dart
@@ -62,7 +62,9 @@ class BuilderInfo {
       dynamic defaultOrMaker,
       CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
+      bool? sparseEnum,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
       {String? protoName}) {
     final index = byIndex.length;
     final fieldInfo = (tagNumber == 0)
@@ -71,7 +73,9 @@ class BuilderInfo {
             defaultOrMaker: defaultOrMaker,
             subBuilder: subBuilder,
             valueOf: valueOf,
+            sparseEnum: sparseEnum,
             enumValues: enumValues,
+            enumValuesByTag: enumValuesByTag,
             protoName: protoName);
     _addField(fieldInfo);
   }
@@ -99,6 +103,8 @@ class BuilderInfo {
       CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
+      bool? sparseEnum,
       {ProtobufEnum? defaultEnumValue,
       String? protoName}) {
     final index = byIndex.length;
@@ -106,6 +112,8 @@ class BuilderInfo {
         name, tagNumber, index, fieldType, check, subBuilder,
         valueOf: valueOf,
         enumValues: enumValues,
+        enumValuesByTag: enumValuesByTag,
+        sparseEnum: sparseEnum,
         defaultEnumValue: defaultEnumValue,
         protoName: protoName));
   }
@@ -127,42 +135,48 @@ class BuilderInfo {
       {dynamic defaultOrMaker,
       CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
+      bool? sparseEnum,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum>? enumValuesByTag,
       String? protoName}) {
     add<T>(tagNumber, name, fieldType, defaultOrMaker, subBuilder, valueOf,
-        enumValues,
+        sparseEnum, enumValues, enumValuesByTag,
         protoName: protoName);
   }
 
   /// Adds PbFieldType.OS String with no default value to reduce generated
   /// code size.
   void aOS(int tagNumber, String name, {String? protoName}) {
-    add<String>(tagNumber, name, PbFieldType.OS, null, null, null, null,
+    add<String>(
+        tagNumber, name, PbFieldType.OS, null, null, null, null, null, null,
         protoName: protoName);
   }
 
   /// Adds PbFieldType.PS String with no default value.
   void pPS(int tagNumber, String name, {String? protoName}) {
     addRepeated<String>(tagNumber, name, PbFieldType.PS,
-        getCheckFunction(PbFieldType.PS), null, null, null,
+        getCheckFunction(PbFieldType.PS), null, null, null, null, null,
         protoName: protoName);
   }
 
   /// Adds PbFieldType.QS String with no default value.
   void aQS(int tagNumber, String name, {String? protoName}) {
-    add<String>(tagNumber, name, PbFieldType.QS, null, null, null, null,
+    add<String>(
+        tagNumber, name, PbFieldType.QS, null, null, null, null, null, null,
         protoName: protoName);
   }
 
   /// Adds Int64 field with Int64.ZERO default.
   void aInt64(int tagNumber, String name, {String? protoName}) {
     add<Int64>(tagNumber, name, PbFieldType.O6, Int64.ZERO, null, null, null,
+        null, null,
         protoName: protoName);
   }
 
   /// Adds a boolean with no default value.
   void aOB(int tagNumber, String name, {String? protoName}) {
-    add<bool>(tagNumber, name, PbFieldType.OB, null, null, null, null,
+    add<bool>(
+        tagNumber, name, PbFieldType.OB, null, null, null, null, null, null,
         protoName: protoName);
   }
 
@@ -170,10 +184,12 @@ class BuilderInfo {
   void e<T>(int tagNumber, String name, int fieldType,
       {dynamic defaultOrMaker,
       ValueOfFunc? valueOf,
+      bool? sparseEnum,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
       String? protoName}) {
-    add<T>(
-        tagNumber, name, fieldType, defaultOrMaker, null, valueOf, enumValues,
+    add<T>(tagNumber, name, fieldType, defaultOrMaker, null, valueOf,
+        sparseEnum, enumValues, enumValuesByTag,
         protoName: protoName);
   }
 
@@ -181,7 +197,7 @@ class BuilderInfo {
   void p<T>(int tagNumber, String name, int fieldType, {String? protoName}) {
     assert(!_isGroupOrMessage(fieldType) && !_isEnum(fieldType));
     addRepeated<T>(tagNumber, name, fieldType, getCheckFunction(fieldType),
-        null, null, null,
+        null, null, null, null, null,
         protoName: protoName);
   }
 
@@ -189,12 +205,14 @@ class BuilderInfo {
   void pc<T>(int tagNumber, String name, int fieldType,
       {CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
+      bool? sparseEnum,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
       ProtobufEnum? defaultEnumValue,
       String? protoName}) {
     assert(_isGroupOrMessage(fieldType) || _isEnum(fieldType));
     addRepeated<T>(tagNumber, name, fieldType, _checkNotNull, subBuilder,
-        valueOf, enumValues,
+        valueOf, enumValues, enumValuesByTag, sparseEnum,
         defaultEnumValue: defaultEnumValue, protoName: protoName);
   }
 
@@ -208,6 +226,8 @@ class BuilderInfo {
         subBuilder,
         null,
         null,
+        null,
+        null,
         protoName: protoName);
   }
 
@@ -221,6 +241,8 @@ class BuilderInfo {
         subBuilder,
         null,
         null,
+        null,
+        null,
         protoName: protoName);
   }
 
@@ -238,16 +260,27 @@ class BuilderInfo {
       required int valueFieldType,
       CreateBuilderFunc? valueCreator,
       ValueOfFunc? valueOf,
+      bool? sparseEnum,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
       ProtobufEnum? defaultEnumValue,
       PackageName packageName = const PackageName(''),
       String? protoName,
       dynamic valueDefaultOrMaker}) {
-    final mapEntryBuilderInfo = BuilderInfo(entryClassName,
-        package: packageName)
-      ..add(PbMap._keyFieldNumber, 'key', keyFieldType, null, null, null, null)
-      ..add(PbMap._valueFieldNumber, 'value', valueFieldType,
-          valueDefaultOrMaker, valueCreator, valueOf, enumValues);
+    final mapEntryBuilderInfo =
+        BuilderInfo(entryClassName, package: packageName)
+          ..add(PbMap._keyFieldNumber, 'key', keyFieldType, null, null, null,
+              null, null, null)
+          ..add(
+              PbMap._valueFieldNumber,
+              'value',
+              valueFieldType,
+              valueDefaultOrMaker,
+              valueCreator,
+              valueOf,
+              sparseEnum,
+              enumValues,
+              enumValuesByTag);
 
     addMapField<K, V>(tagNumber, name, keyFieldType, valueFieldType,
         mapEntryBuilderInfo, valueCreator,
@@ -323,13 +356,31 @@ class BuilderInfo {
 
   ProtobufEnum? _decodeEnum(
       int tagNumber, ExtensionRegistry? registry, int rawValue) {
-    final f = valueOfFunc(tagNumber);
-    if (f != null) {
-      return f(rawValue);
+    final fi = fieldInfo[tagNumber];
+    if (fi == null) {
+      return _decodeEnumExtension(tagNumber, registry, rawValue);
+    }
+
+    final valuesByTag = fi.enumValuesByTag;
+    if (valuesByTag == null) {
+      return _decodeEnumExtension(tagNumber, registry, rawValue);
+    }
+
+    if (fi.sparseEnum) {
+      return ProtobufEnum.$_binarySearch(valuesByTag, rawValue);
+    } else {
+      if (rawValue >= 0 && rawValue < valuesByTag.length) {
+        return valuesByTag[rawValue];
+      } else {
+        return null;
+      }
     }
-    return registry
-        ?.getExtension(qualifiedMessageName, tagNumber)
-        ?.valueOf
-        ?.call(rawValue);
   }
+
+  ProtobufEnum? _decodeEnumExtension(
+          int tagNumber, ExtensionRegistry? registry, int rawValue) =>
+      registry
+          ?.getExtension(qualifiedMessageName, tagNumber)
+          ?.valueOf
+          ?.call(rawValue);
 }
diff --git a/protobuf/lib/src/protobuf/extension.dart b/protobuf/lib/src/protobuf/extension.dart
index 1144443f..9736d172 100644
--- a/protobuf/lib/src/protobuf/extension.dart
+++ b/protobuf/lib/src/protobuf/extension.dart
@@ -13,12 +13,16 @@ class Extension<T> extends FieldInfo<T> {
       CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
+      bool? sparseEnum,
       String? protoName})
       : super(name, tagNumber, null, fieldType,
             defaultOrMaker: defaultOrMaker,
             subBuilder: subBuilder,
             valueOf: valueOf,
             enumValues: enumValues,
+            enumValuesByTag: enumValuesByTag,
+            sparseEnum: sparseEnum,
             protoName: protoName);
 
   Extension.repeated(this.extendee, String name, int tagNumber, int fieldType,
@@ -26,9 +30,15 @@ class Extension<T> extends FieldInfo<T> {
       CreateBuilderFunc? subBuilder,
       ValueOfFunc? valueOf,
       List<ProtobufEnum>? enumValues,
+      List<ProtobufEnum?>? enumValuesByTag,
+      bool? sparseEnum,
       String? protoName})
       : super.repeated(name, tagNumber, null, fieldType, check, subBuilder,
-            valueOf: valueOf, enumValues: enumValues, protoName: protoName);
+            valueOf: valueOf,
+            enumValues: enumValues,
+            enumValuesByTag: enumValuesByTag,
+            sparseEnum: sparseEnum,
+            protoName: protoName);
 
   @override
   int get hashCode => extendee.hashCode * 31 + tagNumber;
diff --git a/protobuf/lib/src/protobuf/field_info.dart b/protobuf/lib/src/protobuf/field_info.dart
index 1777e090..db4034d4 100644
--- a/protobuf/lib/src/protobuf/field_info.dart
+++ b/protobuf/lib/src/protobuf/field_info.dart
@@ -78,11 +78,14 @@ class FieldInfo<T> {
   /// Only available in fields with message type.
   final CreateBuilderFunc? subBuilder;
 
-  /// List of all enum values.
+  /// List of all enum values, in the order they appear in the proto definition.
+  /// (not sorted by enum name or value)
   ///
   /// Only available in enum fields.
   final List<ProtobufEnum>? enumValues;
 
+  final List<ProtobufEnum?>? enumValuesByTag;
+
   /// Default enum value.
   ///
   /// Only available in enum fields.
@@ -93,6 +96,14 @@ class FieldInfo<T> {
   /// Only available in enum fields.
   final ValueOfFunc? valueOf;
 
+  /// Tells the binary decoder how to search in the enum list by tag.
+  ///
+  /// When the enum is "sparse", the decoder binarys earches.
+  ///
+  /// Otherwise the decoder indexes the list (after a range check) with the enum
+  /// value on the wire.
+  final bool sparseEnum;
+
   /// Function to verify items when adding to a repeated field.
   ///
   /// Only available in repeated fields.
@@ -103,9 +114,12 @@ class FieldInfo<T> {
       this.subBuilder,
       this.valueOf,
       this.enumValues,
+      this.enumValuesByTag,
+      bool? sparseEnum,
       this.defaultEnumValue,
       String? protoName})
       : makeDefault = findMakeDefault(type, defaultOrMaker),
+        sparseEnum = sparseEnum ?? false,
         check = null,
         _protoName = protoName,
         assert(type != 0),
@@ -122,16 +136,24 @@ class FieldInfo<T> {
         type = 0,
         makeDefault = null,
         valueOf = null,
+        sparseEnum = false,
         check = null,
         enumValues = null,
+        enumValuesByTag = null,
         defaultEnumValue = null,
         subBuilder = null;
 
   FieldInfo.repeated(this.name, this.tagNumber, this.index, this.type,
       CheckFunc<T> this.check, this.subBuilder,
-      {this.valueOf, this.enumValues, this.defaultEnumValue, String? protoName})
+      {this.valueOf,
+      bool? sparseEnum,
+      this.enumValues,
+      this.enumValuesByTag,
+      this.defaultEnumValue,
+      String? protoName})
       : makeDefault = (() => PbList<T>(check: check)),
         _protoName = protoName,
+        sparseEnum = sparseEnum ?? false,
         assert(_isRepeated(type)),
         assert(!_isEnum(type) || valueOf != null);
 
@@ -277,7 +299,7 @@ class MapFieldInfo<K, V> extends FieldInfo<PbMap<K, V>?> {
             defaultOrMaker: () => PbMap<K, V>(keyFieldType, valueFieldType),
             defaultEnumValue: defaultEnumValue,
             protoName: protoName) {
-    assert(!_isEnum(type) || valueOf != null);
+    assert(!_isEnum(type) || (valueOf != null && sparseEnum != null));
   }
 
   FieldInfo get valueFieldInfo =>
diff --git a/protobuf/lib/src/protobuf/protobuf_enum.dart b/protobuf/lib/src/protobuf/protobuf_enum.dart
index b96c119a..4168be27 100644
--- a/protobuf/lib/src/protobuf/protobuf_enum.dart
+++ b/protobuf/lib/src/protobuf/protobuf_enum.dart
@@ -2,21 +2,25 @@
 // 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.
 
+// ignore_for_file: non_constant_identifier_names
+
 part of '../../protobuf.dart';
 
 /// A base class for all proto enum types.
 ///
-/// All proto `enum` classes inherit from [ProtobufEnum]. For example, given
-/// the following enum defined in a proto file:
+/// All proto `enum` classes inherit from [ProtobufEnum]. For example, given the
+/// following enum defined in a proto file:
 ///
-///     message MyMessage {
-///       enum Color {
-///         RED = 0;
-///         GREEN = 1;
-///         BLUE = 2;
-///       };
-///       // ...
-///     }
+/// ```
+/// message MyMessage {
+///   enum Color {
+///     RED = 0;
+///     GREEN = 1;
+///     BLUE = 2;
+///   };
+///   // ...
+/// }
+/// ```
 ///
 /// the generated Dart file will include a `MyMessage_Color` class that extends
 /// `ProtobufEnum`. It will also include a `const MyMessage_Color` for each of
@@ -37,16 +41,39 @@ class ProtobufEnum {
   /// Creates a new constant [ProtobufEnum] using [value] and [name].
   const ProtobufEnum(this.value, this.name);
 
-  /// Creates a Map for all of the [ProtobufEnum]s in [byIndex], mapping each
-  /// [ProtobufEnum]'s [value] to the [ProtobufEnum].
-  static Map<int, T> initByValue<T extends ProtobufEnum>(List<T> byIndex) {
-    final byValue = <int, T>{};
-    for (final v in byIndex) {
-      byValue[v.value] = v;
+  /// @nodoc
+  static List<T?> $_initDenseList<T extends ProtobufEnum>(List<T> byIndex) {
+    if (byIndex.isEmpty) return [];
+    final byValue = List<T?>.filled(byIndex.last.value + 1, null);
+    for (final enumValue in byIndex) {
+      byValue[enumValue.value] = enumValue;
     }
     return byValue;
   }
 
+  /// @nodoc
+  static List<T> $_initSparseList<T extends ProtobufEnum>(List<T> byIndex) =>
+      byIndex.toList()..sort((e1, e2) => e1.value.compareTo(e2.value));
+
+  /// @nodoc
+  static T? $_binarySearch<T extends ProtobufEnum>(
+      List<T?> sortedList, int value) {
+    var min = 0;
+    var max = sortedList.length;
+    while (min < max) {
+      final mid = min + ((max - min) >> 1);
+      final element = sortedList[mid];
+      final comp = element!.value.compareTo(value);
+      if (comp == 0) return element;
+      if (comp < 0) {
+        min = mid + 1;
+      } else {
+        max = mid;
+      }
+    }
+    return null;
+  }
+
   /// Returns this enum's [name] or the [value] if names are not represented.
   @override
   String toString() => name == '' ? value.toString() : name;
diff --git a/protoc_plugin/lib/protoc.dart b/protoc_plugin/lib/protoc.dart
index e6d175bd..2ce0dd0a 100644
--- a/protoc_plugin/lib/protoc.dart
+++ b/protoc_plugin/lib/protoc.dart
@@ -1,5 +1,6 @@
 import 'dart:convert';
 
+import 'package:collection/collection.dart';
 import 'package:protobuf/protobuf.dart';
 
 import 'const_generator.dart' show writeJsonConst;
diff --git a/protoc_plugin/lib/src/enum_generator.dart b/protoc_plugin/lib/src/enum_generator.dart
index a1cd8b5f..8fb72eb3 100644
--- a/protoc_plugin/lib/src/enum_generator.dart
+++ b/protoc_plugin/lib/src/enum_generator.dart
@@ -102,6 +102,9 @@ class EnumGenerator extends ProtobufContainer {
   static const int _enumValueTag = 2;
 
   void generate(IndentingWriter out) {
+    assert(_canonicalValues
+        .isSortedBy<num>((EnumValueDescriptorProto a) => a.number));
+
     final commentBlock = fileGen?.commentBlock(fieldPath);
     if (commentBlock != null) {
       out.println(commentBlock);
@@ -165,7 +168,6 @@ class EnumGenerator extends ProtobufContainer {
         }
       }
       out.println();
-
       out.println('static const $coreImportPrefix.List<$classname> values ='
           ' <$classname> [');
       for (final val in _canonicalValues) {
@@ -175,11 +177,38 @@ class EnumGenerator extends ProtobufContainer {
       out.println('];');
       out.println();
 
-      out.println(
-          'static final $coreImportPrefix.Map<$coreImportPrefix.int, $classname> _byValue ='
-          ' $protobufImportPrefix.ProtobufEnum.initByValue(values);');
-      out.println('static $classname? valueOf($coreImportPrefix.int value) =>'
-          ' _byValue[value];');
+      var useList = _canonicalValues.isEmpty;
+      if (_canonicalValues.isNotEmpty) {
+        if (_canonicalValues.every((val) => !val.number.isNegative)) {
+          if (_canonicalValues.length / (_canonicalValues.last.number + 1) >=
+              0.7) {
+            useList = true;
+          }
+        }
+      }
+
+      if (useList) {
+        out.println(
+            'static final $coreImportPrefix.List<$classname?> enumValuesByTag ='
+            ' $protobufImportPrefix.ProtobufEnum.\$_initDenseList(values);');
+
+        out.println(
+            'static final $coreImportPrefix.bool \$_sparseEnum = false;');
+
+        out.println('static $classname? valueOf($coreImportPrefix.int value) =>'
+            '  value < 0 || value >= enumValuesByTag.length ? null : enumValuesByTag[value];');
+      } else {
+        out.println(
+            'static final $coreImportPrefix.List<$classname> enumValuesByTag ='
+            ' $protobufImportPrefix.ProtobufEnum.\$_initSparseList(values);');
+
+        out.println(
+            'static final $coreImportPrefix.bool \$_sparseEnum = true;');
+
+        out.println('static $classname? valueOf($coreImportPrefix.int value) =>'
+            ' $protobufImportPrefix.ProtobufEnum.\$_binarySearch(enumValuesByTag, value);');
+      }
+
       out.println();
 
       out.println('const $classname._(super.v, super.n);');
diff --git a/protoc_plugin/lib/src/extension_generator.dart b/protoc_plugin/lib/src/extension_generator.dart
index f9eef30f..bf7a5568 100644
--- a/protoc_plugin/lib/src/extension_generator.dart
+++ b/protoc_plugin/lib/src/extension_generator.dart
@@ -121,6 +121,8 @@ class ExtensionGenerator {
       } else if (type.isEnum) {
         named['valueOf'] = '$dartType.valueOf';
         named['enumValues'] = '$dartType.values';
+        named['enumValuesByTag'] = '$dartType.enumValuesByTag';
+        named['sparseEnum'] = '$dartType.\$_sparseEnum';
       }
     } else {
       invocation = '$protobufImportPrefix.Extension<$dartType>';
@@ -131,6 +133,8 @@ class ExtensionGenerator {
         final dartEnum = type.getDartType(fileGen!);
         named['valueOf'] = '$dartEnum.valueOf';
         named['enumValues'] = '$dartEnum.values';
+        named['enumValuesByTag'] = '$dartEnum.enumValuesByTag';
+        named['sparseEnum'] = '$dartEnum.\$_sparseEnum';
       }
     }
     final fieldDefinition = 'static final ';
diff --git a/protoc_plugin/lib/src/generated/descriptor.pb.dart b/protoc_plugin/lib/src/generated/descriptor.pb.dart
index a4dfd4cb..32b5a596 100644
--- a/protoc_plugin/lib/src/generated/descriptor.pb.dart
+++ b/protoc_plugin/lib/src/generated/descriptor.pb.dart
@@ -768,12 +768,16 @@ class FieldDescriptorProto extends $pb.GeneratedMessage {
         4, _omitFieldNames ? '' : 'label', $pb.PbFieldType.OE,
         defaultOrMaker: FieldDescriptorProto_Label.LABEL_OPTIONAL,
         valueOf: FieldDescriptorProto_Label.valueOf,
-        enumValues: FieldDescriptorProto_Label.values)
+        enumValues: FieldDescriptorProto_Label.values,
+        enumValuesByTag: FieldDescriptorProto_Label.enumValuesByTag,
+        sparseEnum: FieldDescriptorProto_Label.$_sparseEnum)
     ..e<FieldDescriptorProto_Type>(
         5, _omitFieldNames ? '' : 'type', $pb.PbFieldType.OE,
         defaultOrMaker: FieldDescriptorProto_Type.TYPE_DOUBLE,
         valueOf: FieldDescriptorProto_Type.valueOf,
-        enumValues: FieldDescriptorProto_Type.values)
+        enumValues: FieldDescriptorProto_Type.values,
+        enumValuesByTag: FieldDescriptorProto_Type.enumValuesByTag,
+        sparseEnum: FieldDescriptorProto_Type.$_sparseEnum)
     ..aOS(6, _omitFieldNames ? '' : 'typeName')
     ..aOS(7, _omitFieldNames ? '' : 'defaultValue')
     ..aOM<FieldOptions>(8, _omitFieldNames ? '' : 'options',
@@ -1734,7 +1738,9 @@ class FileOptions extends $pb.GeneratedMessage {
         9, _omitFieldNames ? '' : 'optimizeFor', $pb.PbFieldType.OE,
         defaultOrMaker: FileOptions_OptimizeMode.SPEED,
         valueOf: FileOptions_OptimizeMode.valueOf,
-        enumValues: FileOptions_OptimizeMode.values)
+        enumValues: FileOptions_OptimizeMode.values,
+        enumValuesByTag: FileOptions_OptimizeMode.enumValuesByTag,
+        sparseEnum: FileOptions_OptimizeMode.$_sparseEnum)
     ..aOB(10, _omitFieldNames ? '' : 'javaMultipleFiles')
     ..aOS(11, _omitFieldNames ? '' : 'goPackage')
     ..aOB(16, _omitFieldNames ? '' : 'ccGenericServices')
@@ -2313,7 +2319,9 @@ class FieldOptions extends $pb.GeneratedMessage {
         1, _omitFieldNames ? '' : 'ctype', $pb.PbFieldType.OE,
         defaultOrMaker: FieldOptions_CType.STRING,
         valueOf: FieldOptions_CType.valueOf,
-        enumValues: FieldOptions_CType.values)
+        enumValues: FieldOptions_CType.values,
+        enumValuesByTag: FieldOptions_CType.enumValuesByTag,
+        sparseEnum: FieldOptions_CType.$_sparseEnum)
     ..aOB(2, _omitFieldNames ? '' : 'packed')
     ..aOB(3, _omitFieldNames ? '' : 'deprecated')
     ..aOB(5, _omitFieldNames ? '' : 'lazy')
@@ -2321,7 +2329,9 @@ class FieldOptions extends $pb.GeneratedMessage {
         6, _omitFieldNames ? '' : 'jstype', $pb.PbFieldType.OE,
         defaultOrMaker: FieldOptions_JSType.JS_NORMAL,
         valueOf: FieldOptions_JSType.valueOf,
-        enumValues: FieldOptions_JSType.values)
+        enumValues: FieldOptions_JSType.values,
+        enumValuesByTag: FieldOptions_JSType.enumValuesByTag,
+        sparseEnum: FieldOptions_JSType.$_sparseEnum)
     ..aOB(10, _omitFieldNames ? '' : 'weak')
     ..pc<UninterpretedOption>(
         999, _omitFieldNames ? '' : 'uninterpretedOption', $pb.PbFieldType.PM,
@@ -2822,7 +2832,9 @@ class MethodOptions extends $pb.GeneratedMessage {
         34, _omitFieldNames ? '' : 'idempotencyLevel', $pb.PbFieldType.OE,
         defaultOrMaker: MethodOptions_IdempotencyLevel.IDEMPOTENCY_UNKNOWN,
         valueOf: MethodOptions_IdempotencyLevel.valueOf,
-        enumValues: MethodOptions_IdempotencyLevel.values)
+        enumValues: MethodOptions_IdempotencyLevel.values,
+        enumValuesByTag: MethodOptions_IdempotencyLevel.enumValuesByTag,
+        sparseEnum: MethodOptions_IdempotencyLevel.$_sparseEnum)
     ..pc<UninterpretedOption>(
         999, _omitFieldNames ? '' : 'uninterpretedOption', $pb.PbFieldType.PM,
         subBuilder: UninterpretedOption.create)
diff --git a/protoc_plugin/lib/src/generated/descriptor.pbenum.dart b/protoc_plugin/lib/src/generated/descriptor.pbenum.dart
index dc6f349d..bc63a97d 100644
--- a/protoc_plugin/lib/src/generated/descriptor.pbenum.dart
+++ b/protoc_plugin/lib/src/generated/descriptor.pbenum.dart
@@ -88,9 +88,13 @@ class FieldDescriptorProto_Type extends $pb.ProtobufEnum {
     TYPE_SINT64,
   ];
 
-  static final $core.Map<$core.int, FieldDescriptorProto_Type> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static FieldDescriptorProto_Type? valueOf($core.int value) => _byValue[value];
+  static final $core.List<FieldDescriptorProto_Type?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static FieldDescriptorProto_Type? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const FieldDescriptorProto_Type._(super.v, super.n);
 }
@@ -111,10 +115,13 @@ class FieldDescriptorProto_Label extends $pb.ProtobufEnum {
     LABEL_REPEATED,
   ];
 
-  static final $core.Map<$core.int, FieldDescriptorProto_Label> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
+  static final $core.List<FieldDescriptorProto_Label?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
   static FieldDescriptorProto_Label? valueOf($core.int value) =>
-      _byValue[value];
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const FieldDescriptorProto_Label._(super.v, super.n);
 }
@@ -137,9 +144,13 @@ class FileOptions_OptimizeMode extends $pb.ProtobufEnum {
     LITE_RUNTIME,
   ];
 
-  static final $core.Map<$core.int, FileOptions_OptimizeMode> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static FileOptions_OptimizeMode? valueOf($core.int value) => _byValue[value];
+  static final $core.List<FileOptions_OptimizeMode?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static FileOptions_OptimizeMode? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const FileOptions_OptimizeMode._(super.v, super.n);
 }
@@ -159,9 +170,13 @@ class FieldOptions_CType extends $pb.ProtobufEnum {
     STRING_PIECE,
   ];
 
-  static final $core.Map<$core.int, FieldOptions_CType> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static FieldOptions_CType? valueOf($core.int value) => _byValue[value];
+  static final $core.List<FieldOptions_CType?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static FieldOptions_CType? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const FieldOptions_CType._(super.v, super.n);
 }
@@ -185,9 +200,13 @@ class FieldOptions_JSType extends $pb.ProtobufEnum {
     JS_NUMBER,
   ];
 
-  static final $core.Map<$core.int, FieldOptions_JSType> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static FieldOptions_JSType? valueOf($core.int value) => _byValue[value];
+  static final $core.List<FieldOptions_JSType?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static FieldOptions_JSType? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const FieldOptions_JSType._(super.v, super.n);
 }
@@ -212,10 +231,13 @@ class MethodOptions_IdempotencyLevel extends $pb.ProtobufEnum {
     IDEMPOTENT,
   ];
 
-  static final $core.Map<$core.int, MethodOptions_IdempotencyLevel> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
+  static final $core.List<MethodOptions_IdempotencyLevel?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
   static MethodOptions_IdempotencyLevel? valueOf($core.int value) =>
-      _byValue[value];
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const MethodOptions_IdempotencyLevel._(super.v, super.n);
 }
diff --git a/protoc_plugin/lib/src/generated/plugin.pbenum.dart b/protoc_plugin/lib/src/generated/plugin.pbenum.dart
index 399158c5..b145b453 100644
--- a/protoc_plugin/lib/src/generated/plugin.pbenum.dart
+++ b/protoc_plugin/lib/src/generated/plugin.pbenum.dart
@@ -27,10 +27,13 @@ class CodeGeneratorResponse_Feature extends $pb.ProtobufEnum {
     FEATURE_PROTO3_OPTIONAL,
   ];
 
-  static final $core.Map<$core.int, CodeGeneratorResponse_Feature> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
+  static final $core.List<CodeGeneratorResponse_Feature?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
   static CodeGeneratorResponse_Feature? valueOf($core.int value) =>
-      _byValue[value];
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const CodeGeneratorResponse_Feature._(super.v, super.n);
 }
diff --git a/protoc_plugin/lib/src/protobuf_field.dart b/protoc_plugin/lib/src/protobuf_field.dart
index 7906cbec..6d14bd05 100644
--- a/protoc_plugin/lib/src/protobuf_field.dart
+++ b/protoc_plugin/lib/src/protobuf_field.dart
@@ -240,6 +240,8 @@ class ProtobufField {
       if (value.baseType.isEnum) {
         named['valueOf'] = '$valueType.valueOf';
         named['enumValues'] = '$valueType.values';
+        named['enumValuesByTag'] = '$valueType.enumValuesByTag';
+        named['sparseEnum'] = '$valueType.\$_sparseEnum';
         named['valueDefaultOrMaker'] = value.generateDefaultFunction();
         named['defaultEnumValue'] = value.generateDefaultFunction();
       }
@@ -263,6 +265,8 @@ class ProtobufField {
         } else if (baseType.isEnum) {
           named['valueOf'] = '$type.valueOf';
           named['enumValues'] = '$type.values';
+          named['enumValuesByTag'] = '$type.enumValuesByTag';
+          named['sparseEnum'] = '$type.\$_sparseEnum';
           named['defaultEnumValue'] = generateDefaultFunction();
         }
       }
@@ -275,6 +279,8 @@ class ProtobufField {
         named['defaultOrMaker'] = makeDefault;
         named['valueOf'] = '$type.valueOf';
         named['enumValues'] = '$type.values';
+        named['enumValuesByTag'] = '$type.enumValuesByTag';
+        named['sparseEnum'] = '$type.\$_sparseEnum';
         invocation = 'e<$type>';
       } else if (makeDefault == null) {
         switch (type) {
diff --git a/protoc_plugin/test/goldens/deprecations.pbenum b/protoc_plugin/test/goldens/deprecations.pbenum
index 30bc5d78..ece62ac4 100644
--- a/protoc_plugin/test/goldens/deprecations.pbenum
+++ b/protoc_plugin/test/goldens/deprecations.pbenum
@@ -24,9 +24,13 @@ class A extends $pb.ProtobufEnum {
     A2,
   ];
 
-  static final $core.Map<$core.int, A> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static A? valueOf($core.int value) => _byValue[value];
+  static final $core.List<A?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static A? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const A._(super.v, super.n);
 }
diff --git a/protoc_plugin/test/goldens/doc_comments.pbenum b/protoc_plugin/test/goldens/doc_comments.pbenum
index 7cde50e1..8ea773f1 100644
--- a/protoc_plugin/test/goldens/doc_comments.pbenum
+++ b/protoc_plugin/test/goldens/doc_comments.pbenum
@@ -26,9 +26,13 @@ class A extends $pb.ProtobufEnum {
     A2,
   ];
 
-  static final $core.Map<$core.int, A> _byValue =
-      $pb.ProtobufEnum.initByValue(values);
-  static A? valueOf($core.int value) => _byValue[value];
+  static final $core.List<A?> enumValuesByTag =
+      $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static A? valueOf($core.int value) =>
+      value < 0 || value >= enumValuesByTag.length
+          ? null
+          : enumValuesByTag[value];
 
   const A._(super.v, super.n);
 }
diff --git a/protoc_plugin/test/goldens/enum b/protoc_plugin/test/goldens/enum
index 812247dd..9a659088 100644
--- a/protoc_plugin/test/goldens/enum
+++ b/protoc_plugin/test/goldens/enum
@@ -11,8 +11,9 @@ class PhoneType extends $pb.ProtobufEnum {
     WORK,
   ];
 
-  static final $core.Map<$core.int, PhoneType> _byValue = $pb.ProtobufEnum.initByValue(values);
-  static PhoneType? valueOf($core.int value) => _byValue[value];
+  static final $core.List<PhoneType?> enumValuesByTag = $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static PhoneType? valueOf($core.int value) =>  value < 0 || value >= enumValuesByTag.length ? null : enumValuesByTag[value];
 
   const PhoneType._(super.v, super.n);
 }
diff --git a/protoc_plugin/test/goldens/messageGenerator b/protoc_plugin/test/goldens/messageGenerator
index 5eab0203..7e337042 100644
--- a/protoc_plugin/test/goldens/messageGenerator
+++ b/protoc_plugin/test/goldens/messageGenerator
@@ -6,7 +6,7 @@ class PhoneNumber extends $pb.GeneratedMessage {
 
   static final $pb.BuilderInfo _i = $pb.BuilderInfo(_omitMessageNames ? '' : 'PhoneNumber', createEmptyInstance: create)
     ..aQS(1, _omitFieldNames ? '' : 'number')
-    ..e<PhoneNumber_PhoneType>(2, _omitFieldNames ? '' : 'type', $pb.PbFieldType.OE, defaultOrMaker: PhoneNumber_PhoneType.MOBILE, valueOf: PhoneNumber_PhoneType.valueOf, enumValues: PhoneNumber_PhoneType.values)
+    ..e<PhoneNumber_PhoneType>(2, _omitFieldNames ? '' : 'type', $pb.PbFieldType.OE, defaultOrMaker: PhoneNumber_PhoneType.MOBILE, valueOf: PhoneNumber_PhoneType.valueOf, enumValues: PhoneNumber_PhoneType.values, enumValuesByTag: PhoneNumber_PhoneType.enumValuesByTag, sparseEnum: PhoneNumber_PhoneType.$_sparseEnum)
     ..a<$core.String>(3, _omitFieldNames ? '' : 'name', $pb.PbFieldType.OS, defaultOrMaker: '\$')
     ..aOS(4, _omitFieldNames ? '' : 'deprecatedField')
   ;
diff --git a/protoc_plugin/test/goldens/messageGenerator.meta b/protoc_plugin/test/goldens/messageGenerator.meta
index c398f603..f8e38f2a 100644
--- a/protoc_plugin/test/goldens/messageGenerator.meta
+++ b/protoc_plugin/test/goldens/messageGenerator.meta
@@ -18,8 +18,8 @@ annotation: {
   path: 2
   path: 1
   sourceFile: 
-  begin: 2003
-  end: 2009
+  begin: 2107
+  end: 2113
 }
 annotation: {
   path: 4
@@ -27,8 +27,8 @@ annotation: {
   path: 2
   path: 1
   sourceFile: 
-  begin: 2051
-  end: 2057
+  begin: 2155
+  end: 2161
 }
 annotation: {
   path: 4
@@ -36,8 +36,8 @@ annotation: {
   path: 2
   path: 1
   sourceFile: 
-  begin: 2130
-  end: 2139
+  begin: 2234
+  end: 2243
 }
 annotation: {
   path: 4
@@ -45,8 +45,8 @@ annotation: {
   path: 2
   path: 1
   sourceFile: 
-  begin: 2182
-  end: 2193
+  begin: 2286
+  end: 2297
 }
 annotation: {
   path: 4
@@ -54,8 +54,8 @@ annotation: {
   path: 2
   path: 0
   sourceFile: 
-  begin: 2265
-  end: 2269
+  begin: 2369
+  end: 2373
 }
 annotation: {
   path: 4
@@ -63,8 +63,8 @@ annotation: {
   path: 2
   path: 0
   sourceFile: 
-  begin: 2310
-  end: 2314
+  begin: 2414
+  end: 2418
 }
 annotation: {
   path: 4
@@ -72,8 +72,8 @@ annotation: {
   path: 2
   path: 0
   sourceFile: 
-  begin: 2395
-  end: 2402
+  begin: 2499
+  end: 2506
 }
 annotation: {
   path: 4
@@ -81,8 +81,8 @@ annotation: {
   path: 2
   path: 0
   sourceFile: 
-  begin: 2445
-  end: 2454
+  begin: 2549
+  end: 2558
 }
 annotation: {
   path: 4
@@ -90,8 +90,8 @@ annotation: {
   path: 2
   path: 2
   sourceFile: 
-  begin: 2517
-  end: 2521
+  begin: 2621
+  end: 2625
 }
 annotation: {
   path: 4
@@ -99,8 +99,8 @@ annotation: {
   path: 2
   path: 2
   sourceFile: 
-  begin: 2568
-  end: 2572
+  begin: 2672
+  end: 2676
 }
 annotation: {
   path: 4
@@ -108,8 +108,8 @@ annotation: {
   path: 2
   path: 2
   sourceFile: 
-  begin: 2645
-  end: 2652
+  begin: 2749
+  end: 2756
 }
 annotation: {
   path: 4
@@ -117,8 +117,8 @@ annotation: {
   path: 2
   path: 2
   sourceFile: 
-  begin: 2695
-  end: 2704
+  begin: 2799
+  end: 2808
 }
 annotation: {
   path: 4
@@ -126,8 +126,8 @@ annotation: {
   path: 2
   path: 3
   sourceFile: 
-  begin: 2816
-  end: 2831
+  begin: 2920
+  end: 2935
 }
 annotation: {
   path: 4
@@ -135,8 +135,8 @@ annotation: {
   path: 2
   path: 3
   sourceFile: 
-  begin: 2922
-  end: 2937
+  begin: 3026
+  end: 3041
 }
 annotation: {
   path: 4
@@ -144,8 +144,8 @@ annotation: {
   path: 2
   path: 3
   sourceFile: 
-  begin: 3059
-  end: 3077
+  begin: 3163
+  end: 3181
 }
 annotation: {
   path: 4
@@ -153,6 +153,6 @@ annotation: {
   path: 2
   path: 3
   sourceFile: 
-  begin: 3169
-  end: 3189
+  begin: 3273
+  end: 3293
 }
diff --git a/protoc_plugin/test/goldens/messageGeneratorEnums b/protoc_plugin/test/goldens/messageGeneratorEnums
index 3469c7ba..b6dbeffd 100644
--- a/protoc_plugin/test/goldens/messageGeneratorEnums
+++ b/protoc_plugin/test/goldens/messageGeneratorEnums
@@ -11,8 +11,9 @@ class PhoneNumber_PhoneType extends $pb.ProtobufEnum {
     WORK,
   ];
 
-  static final $core.Map<$core.int, PhoneNumber_PhoneType> _byValue = $pb.ProtobufEnum.initByValue(values);
-  static PhoneNumber_PhoneType? valueOf($core.int value) => _byValue[value];
+  static final $core.List<PhoneNumber_PhoneType?> enumValuesByTag = $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static PhoneNumber_PhoneType? valueOf($core.int value) =>  value < 0 || value >= enumValuesByTag.length ? null : enumValuesByTag[value];
 
   const PhoneNumber_PhoneType._(super.v, super.n);
 }
diff --git a/protoc_plugin/test/goldens/topLevelEnum.pbenum b/protoc_plugin/test/goldens/topLevelEnum.pbenum
index 30d81a24..8deb35d5 100644
--- a/protoc_plugin/test/goldens/topLevelEnum.pbenum
+++ b/protoc_plugin/test/goldens/topLevelEnum.pbenum
@@ -26,8 +26,9 @@ class PhoneType extends $pb.ProtobufEnum {
     WORK,
   ];
 
-  static final $core.Map<$core.int, PhoneType> _byValue = $pb.ProtobufEnum.initByValue(values);
-  static PhoneType? valueOf($core.int value) => _byValue[value];
+  static final $core.List<PhoneType?> enumValuesByTag = $pb.ProtobufEnum.$_initDenseList(values);
+  static final $core.bool $_sparseEnum = false;
+  static PhoneType? valueOf($core.int value) =>  value < 0 || value >= enumValuesByTag.length ? null : enumValuesByTag[value];
 
   const PhoneType._(super.v, super.n);
 }