diff --git a/lib/bazel.dart b/lib/bazel.dart
index 6bfe90a..f66cb65 100644
--- a/lib/bazel.dart
+++ b/lib/bazel.dart
@@ -105,7 +105,7 @@
   }
 
   @override
-  Uri outputPathFor(Uri input) {
+  Uri outputPathFor(Uri input, String extension) {
     var pkg = _findPackage(input.path);
     if (pkg == null) {
       throw new ArgumentError('Unable to locate package for input $input.');
@@ -113,14 +113,15 @@
 
     // Bazel package-relative paths.
     var relativeInput = input.path.substring('${pkg.input_root}/'.length);
-    var relativeOutput = replacePathExtension(relativeInput);
-    var outputPath = p.join(pkg.output_root, relativeOutput);
+    var base = p.withoutExtension(relativeInput);
+    var outputPath = p.join(pkg.output_root, "$base$extension");
     return new Uri.file(outputPath);
   }
 
   @override
-  Uri resolveImport(Uri target, Uri source) {
-    var targetUri = _packageUriFor(replacePathExtension(target.path));
+  Uri resolveImport(Uri target, Uri source, String extension) {
+    var targetBase = p.withoutExtension(target.path);
+    var targetUri = _packageUriFor("$targetBase$extension");
     var sourceUri = _packageUriFor(source.path);
 
     if (targetUri == null && sourceUri != null) {
@@ -134,7 +135,7 @@
       return targetUri.uri;
     }
 
-    return super.resolveImport(target, source);
+    return super.resolveImport(target, source, extension);
   }
 
   _PackageUri _packageUriFor(String target) {
diff --git a/lib/code_generator.dart b/lib/code_generator.dart
index 2072de2..92561a4 100644
--- a/lib/code_generator.dart
+++ b/lib/code_generator.dart
@@ -66,6 +66,7 @@
         var name = gen._fileDescriptor.name;
         if (request.fileToGenerate.contains(name)) {
           response.file.add(gen.generateResponse(config));
+          response.file.add(gen.generateEnumResponse(config));
           response.file.add(gen.generateJsonDartResponse(config));
         }
       }
diff --git a/lib/extension_generator.dart b/lib/extension_generator.dart
index 91260aa..e675750 100644
--- a/lib/extension_generator.dart
+++ b/lib/extension_generator.dart
@@ -44,15 +44,20 @@
   ///
   /// For each .pb.dart file that the generated code needs to import,
   /// add its generator.
-  void addImportsTo(Set<FileGenerator> imports) {
+  void addImportsTo(
+      Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
     if (_field == null) throw new StateError("resolve not called");
     var typeGen = _field.baseType.generator;
     if (typeGen != null && typeGen.fileGen != fileGen) {
       // The type of this extension is defined in a different file,
       // so we need to import it.
+      if (typeGen is EnumGenerator) {
+        enumImports.add(typeGen.fileGen);
+      } else {
       imports.add(typeGen.fileGen);
     }
   }
+  }
 
   /// Adds dependencies of [generateConstants] to [imports].
   ///
diff --git a/lib/file_generator.dart b/lib/file_generator.dart
index 76c5a7f..f1f78f2 100644
--- a/lib/file_generator.dart
+++ b/lib/file_generator.dart
@@ -118,7 +118,7 @@
 
     Uri filePath = new Uri.file(_fileDescriptor.name);
     return new CodeGeneratorResponse_File()
-      ..name = config.outputPathFor(filePath).path
+      ..name = config.outputPathFor(filePath, ".pb.dart").path
       ..content = out.toString();
   }
 
@@ -130,9 +130,6 @@
     generateHeader(out, config);
 
     // Generate code.
-    for (EnumGenerator e in enumGenerators) {
-      e.generate(out);
-    }
     for (MessageGenerator m in messageGenerators) {
       m.generate(out);
     }
@@ -181,7 +178,11 @@
     if (_needsFixnumImport) {
       out.println("import 'package:fixnum/fixnum.dart';");
     }
+
+    if (_needsProtobufImport) {
     out.println("import 'package:protobuf/protobuf.dart';");
+      out.println();
+    }
 
     var mixinImports = findMixinsToImport();
     var importNames = mixinImports.keys.toList();
@@ -190,23 +191,46 @@
       var symbols = mixinImports[imp];
       out.println("import '${imp}' show ${symbols.join(', ')};");
     }
+    if (mixinImports.isNotEmpty) out.println();
 
     // Import the .pb.dart files we depend on.
-    for (var imported in _findProtosToImport()) {
+    var imports = new Set<FileGenerator>.identity();
+    var enumImports = new Set<FileGenerator>.identity();
+    _findProtosToImport(imports, enumImports);
+
+    void writeImport(FileGenerator target, String extension) {
       Uri resolvedImport =
-          config.resolveImport(imported.protoFileUri, protoFileUri);
+          config.resolveImport(target.protoFileUri, protoFileUri, extension);
       out.print("import '$resolvedImport'");
-      if (package != imported.package && imported.package.isNotEmpty) {
-        out.print(' as ${imported.packageImportPrefix}');
+      if (package != target.package && target.package.isNotEmpty) {
+        out.print(' as ${target.packageImportPrefix}');
       }
       out.println(';');
     }
-    out.println();
+
+    for (var target in imports) {
+      writeImport(target, ".pb.dart");
+    }
+    if (imports.isNotEmpty) out.println();
+
+    for (var target in enumImports) {
+      writeImport(target, ".pbenum.dart");
+    }
+    if (enumImports.isNotEmpty) out.println();
 
     // Services also depend on the json imports.
     if (serviceGenerators.isNotEmpty) {
-      Uri resolvedImport = config.resolveJsonImport(protoFileUri, protoFileUri);
-      out.print("import '$resolvedImport';");
+      Uri resolvedImport =
+          config.resolveImport(protoFileUri, protoFileUri, ".pbjson.dart");
+      out.println("import '$resolvedImport';");
+      out.println();
+    }
+
+    // Export enums in main file for backward compatibility.
+    if (enumCount > 0) {
+      Uri resolvedImport =
+          config.resolveImport(protoFileUri, protoFileUri, ".pbenum.dart");
+      out.println("export '$resolvedImport';");
       out.println();
     }
   }
@@ -221,20 +245,26 @@
     return false;
   }
 
+  bool get _needsProtobufImport =>
+      messageGenerators.isNotEmpty ||
+      extensionGenerators.isNotEmpty ||
+      clientApiGenerators.isNotEmpty ||
+      serviceGenerators.isNotEmpty;
+
   /// Returns the generator for each .pb.dart file we need to import.
-  Set<FileGenerator> _findProtosToImport() {
-    var imports = new Set<FileGenerator>.identity();
+  void _findProtosToImport(
+      Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
     for (var m in messageGenerators) {
-      m.addImportsTo(imports);
+      m.addImportsTo(imports, enumImports);
     }
     for (var x in extensionGenerators) {
-      x.addImportsTo(imports);
+      x.addImportsTo(imports, enumImports);
     }
     for (var x in serviceGenerators) {
       x.addImportsTo(imports);
     }
-    imports.remove(this); // Don't need to import self.
-    return imports;
+    // Don't need to import self. (But we may need to import the enums.)
+    imports.remove(this);
   }
 
   /// Returns a map from import names to the Dart symbols to be imported.
@@ -262,6 +292,60 @@
     return imports;
   }
 
+  CodeGeneratorResponse_File generateEnumResponse(OutputConfiguration config) {
+    if (!_linked) throw new StateError("not linked");
+
+    IndentingWriter out = new IndentingWriter();
+
+    generateEnumFile(out, config);
+
+    Uri filePath = new Uri.file(_fileDescriptor.name);
+    return new CodeGeneratorResponse_File()
+      ..name = config.outputPathFor(filePath, ".pbenum.dart").path
+      ..content = out.toString();
+  }
+
+  void generateEnumFile(IndentingWriter out,
+      [OutputConfiguration config = const DefaultOutputConfiguration()]) {
+    Uri filePath = new Uri.file(_fileDescriptor.name);
+    if (filePath.isAbsolute) {
+      // protoc should never generate a file descriptor with an absolute path.
+      throw "FAILURE: File with an absolute path is not supported";
+    }
+
+    var baseLibraryName = _generateLibraryName(filePath);
+    var libraryName = baseLibraryName + "_pbenum";
+    out.print('''
+///
+//  Generated code. Do not modify.
+///
+library $libraryName;
+
+''');
+
+    if (enumCount > 0) {
+      out.println("import 'package:protobuf/protobuf.dart';");
+      out.println();
+    }
+
+    for (EnumGenerator e in enumGenerators) {
+      e.generate(out);
+    }
+
+    for (MessageGenerator m in messageGenerators) {
+      m.generateEnums(out);
+    }
+  }
+
+  /// Returns the number of enum types generated in the .pbenum.dart file.
+  int get enumCount {
+    var count = enumGenerators.length;
+    for (MessageGenerator m in messageGenerators) {
+      count += m.enumCount;
+    }
+    return count;
+  }
+
   CodeGeneratorResponse_File generateJsonDartResponse(
       OutputConfiguration config) {
     if (!_linked) throw new StateError("not linked");
@@ -272,7 +356,7 @@
 
     Uri filePath = new Uri.file(_fileDescriptor.name);
     return new CodeGeneratorResponse_File()
-      ..name = config.jsonDartOutputPathFor(filePath).path
+      ..name = config.outputPathFor(filePath, ".pbjson.dart").path
       ..content = out.toString();
   }
 
@@ -297,8 +381,8 @@
     // Import the .pbjson.dart files we depend on.
     var importList = _findJsonProtosToImport();
     for (var imported in importList) {
-      Uri resolvedImport =
-          config.resolveJsonImport(imported.protoFileUri, protoFileUri);
+      Uri resolvedImport = config.resolveImport(
+          imported.protoFileUri, protoFileUri, ".pbjson.dart");
       out.print("import '$resolvedImport'");
       if (package != imported.package && imported.package.isNotEmpty) {
         out.print(' as ${imported.packageImportPrefix}');
diff --git a/lib/message_generator.dart b/lib/message_generator.dart
index 4384d88..a3d47b6 100644
--- a/lib/message_generator.dart
+++ b/lib/message_generator.dart
@@ -197,24 +197,34 @@
   ///
   /// For each .pb.dart file that the generated code needs to import,
   /// add its generator.
-  void addImportsTo(Set<FileGenerator> imports) {
+  void addImportsTo(
+      Set<FileGenerator> imports, Set<FileGenerator> enumImports) {
     if (_fieldList == null) throw new StateError("message not resolved");
     for (var field in _fieldList) {
       var typeGen = field.baseType.generator;
-      if (typeGen != null && typeGen.fileGen != fileGen) {
-        // The field's type is defined in a different .pb.dart file.
-        // Therefore we need to import it.
+      if (typeGen is EnumGenerator) {
+        enumImports.add(typeGen.fileGen);
+      } else if (typeGen != null) {
         imports.add(typeGen.fileGen);
       }
     }
     for (var m in _messageGenerators) {
-      m.addImportsTo(imports);
+      m.addImportsTo(imports, enumImports);
     }
     for (var x in _extensionGenerators) {
-      x.addImportsTo(imports);
+      x.addImportsTo(imports, enumImports);
     }
   }
 
+  // Returns the number of enums in this message and all nested messages.
+  int get enumCount {
+    var count = _enumGenerators.length;
+    for (var m in _messageGenerators) {
+      count += m.enumCount;
+    }
+    return count;
+  }
+
   /// Adds dependencies of [generateConstants] to [imports].
   ///
   /// For each .pbjson.dart file that the generated code needs to import,
@@ -241,10 +251,6 @@
       _methodNames.addAll(mixin.findReservedNames());
     }
 
-    for (EnumGenerator e in _enumGenerators) {
-      e.generate(out);
-    }
-
     for (MessageGenerator m in _messageGenerators) {
       m.generate(out);
     }
@@ -408,6 +414,16 @@
     }
   }
 
+  void generateEnums(IndentingWriter out) {
+    for (EnumGenerator e in _enumGenerators) {
+      e.generate(out);
+    }
+
+    for (MessageGenerator m in _messageGenerators) {
+      m.generateEnums(out);
+    }
+  }
+
   /// Writes a Dart constant containing the JSON for the ProtoDescriptor.
   /// Also writes a separate constant for each nested message,
   /// to avoid duplication.
diff --git a/lib/output_config.dart b/lib/output_config.dart
index 481d03d..534f24e 100644
--- a/lib/output_config.dart
+++ b/lib/output_config.dart
@@ -9,46 +9,20 @@
 abstract class OutputConfiguration {
   const OutputConfiguration();
 
-  /// Returns [filePath] with it's extension replaced with '.pb.dart'.
-  String replacePathExtension(String filePath) =>
-      '${path.withoutExtension(filePath)}.pb.dart';
-
-  /// Returns [file] with it's extension replaced with '.pb.dart'.
-  Uri replaceUriExtension(Uri file) =>
-      path.url.toUri(replacePathExtension(path.url.fromUri(file)));
-
-  /// Resolves an import of a .pb.dart file.
+  /// Resolves an import of a generated Dart file.
   ///
   /// Both [source] and [target] are .proto files, where [source] imports
   /// [target].
   ///
-  /// The returned URI can be used within the source's .pb.dart file to
-  /// import the target's .pb.dart file.
-  Uri resolveImport(Uri target, Uri source);
-
-  /// Resolves an import of a .pbjson.dart file.
-  ///
-  /// Both [source] and [target] are .proto files, where [source] imports
-  /// [target].
-  ///
-  /// The returned URI can be used within the source's .pbjson.dart file to
-  /// import the target's .pbjson.dart file.
-  Uri resolveJsonImport(Uri target, Uri source);
+  /// The returned URI can be used within one of the source's dart files to
+  /// import the target's generated file with the given extension.
+  Uri resolveImport(Uri target, Uri source, String extension);
 
   /// Returns the path where the .pb.dart file will be placed.
   ///
   /// The input is a .proto file and the output is a path under the output
   /// folder.
-  Uri outputPathFor(Uri inputPath);
-
-  /// Returns the path where the .pbjson.dart file will be place.
-  ///
-  /// The input is a .proto file and the output is a path under the output
-  /// folder.
-  ///
-  /// (This file making data from the .proto file available as
-  /// constants in Dart. The constants are JSON-encoded protobufs.)
-  Uri jsonDartOutputPathFor(Uri inputPath);
+  Uri outputPathFor(Uri inputPath, String extension);
 }
 
 /// Default [OutputConfiguration] that uses the same path as the input
@@ -58,28 +32,17 @@
   const DefaultOutputConfiguration();
 
   @override
-  Uri outputPathFor(Uri input) => replaceUriExtension(input);
-
-  @override
-  Uri jsonDartOutputPathFor(Uri input) {
+  Uri outputPathFor(Uri input, String extension) {
     var base = path.withoutExtension(path.url.fromUri(input));
-    return path.url.toUri('$base.pbjson.dart');
+    return path.url.toUri('$base$extension');
   }
 
   @override
-  Uri resolveImport(Uri target, Uri source) {
-    var targetPath = path.url.fromUri(target);
-    var sourceDir = path.url.dirname(path.url.fromUri(source));
-    return path.url.toUri(
-        replacePathExtension(path.url.relative(targetPath, from: sourceDir)));
-  }
-
-  @override
-  Uri resolveJsonImport(Uri target, Uri source) {
+  Uri resolveImport(Uri target, Uri source, String extension) {
     var targetPath = path.url.fromUri(target);
     var sourceDir = path.url.dirname(path.url.fromUri(source));
     var base =
         path.withoutExtension(path.url.relative(targetPath, from: sourceDir));
-    return path.url.toUri('$base.pbjson.dart');
+    return path.url.toUri('$base$extension');
   }
 }
diff --git a/test/bazel_test.dart b/test/bazel_test.dart
index 7f1773d..64ed08a 100644
--- a/test/bazel_test.dart
+++ b/test/bazel_test.dart
@@ -112,7 +112,7 @@
 
   group('BazelOutputConfiguration', () {
     Map<String, BazelPackage> packages;
-    var config;
+    BazelOutputConfiguration config;
 
     setUp(() {
       packages = {
@@ -126,28 +126,34 @@
 
     group('outputPathForUri', () {
       test('should handle files at package root', () {
-        var p = config.outputPathFor(Uri.parse('foo/bar/quux.proto'));
+        var p =
+            config.outputPathFor(Uri.parse('foo/bar/quux.proto'), '.pb.dart');
         expect(p.path, 'baz/flob/quux.pb.dart');
       });
 
       test('should handle files below package root', () {
-        var p = config.outputPathFor(Uri.parse('foo/bar/a/b/quux.proto'));
+        var p = config.outputPathFor(
+            Uri.parse('foo/bar/a/b/quux.proto'), '.pb.dart');
         expect(p.path, 'baz/flob/a/b/quux.pb.dart');
       });
 
       test('should handle files in a nested package root', () {
-        var p = config.outputPathFor(Uri.parse('foo/bar/baz/quux.proto'));
+        var p = config.outputPathFor(
+            Uri.parse('foo/bar/baz/quux.proto'), '.pb.dart');
         expect(p.path, 'baz/flob/foo/quux.pb.dart');
       });
 
       test('should handle files below a nested package root', () {
-        var p = config.outputPathFor(Uri.parse('foo/bar/baz/a/b/quux.proto'));
+        var p = config.outputPathFor(
+            Uri.parse('foo/bar/baz/a/b/quux.proto'), '.pb.dart');
         expect(p.path, 'baz/flob/foo/a/b/quux.pb.dart');
       });
 
       test('should throw if unable to locate the package for an input', () {
         expect(
-            () => config.outputPathFor(Uri.parse('a/b/c/quux.proto')), throws);
+            () =>
+                config.outputPathFor(Uri.parse('a/b/c/quux.proto'), '.pb.dart'),
+            throws);
       });
     });
 
@@ -155,28 +161,28 @@
       test('should emit relative import if in same package', () {
         var target = Uri.parse('foo/bar/quux.proto');
         var source = Uri.parse('foo/bar/baz.proto');
-        var uri = config.resolveImport(target, source);
+        var uri = config.resolveImport(target, source, '.pb.dart');
         expect(uri.path, 'quux.pb.dart');
       });
 
       test('should emit relative import if in subdir of same package', () {
         var target = Uri.parse('foo/bar/a/b/quux.proto');
         var source = Uri.parse('foo/bar/baz.proto');
-        var uri = config.resolveImport(target, source);
+        var uri = config.resolveImport(target, source, '.pb.dart');
         expect(uri.path, 'a/b/quux.pb.dart');
       });
 
       test('should emit relative import if in parent dir in same package', () {
         var target = Uri.parse('foo/bar/quux.proto');
         var source = Uri.parse('foo/bar/a/b/baz.proto');
-        var uri = config.resolveImport(target, source);
+        var uri = config.resolveImport(target, source, '.pb.dart');
         expect(uri.path, '../../quux.pb.dart');
       });
 
       test('should emit package: import if in different package', () {
         var target = Uri.parse('wibble/wobble/quux.proto');
         var source = Uri.parse('foo/bar/baz.proto');
-        var uri = config.resolveImport(target, source);
+        var uri = config.resolveImport(target, source, '.pb.dart');
         expect(uri.scheme, 'package');
         expect(uri.path, 'wibble.wobble/quux.pb.dart');
       });
@@ -184,7 +190,7 @@
       test('should emit package: import if in subdir of different package', () {
         var target = Uri.parse('wibble/wobble/foo/bar/quux.proto');
         var source = Uri.parse('foo/bar/baz.proto');
-        var uri = config.resolveImport(target, source);
+        var uri = config.resolveImport(target, source, '.pb.dart');
         expect(uri.scheme, 'package');
         expect(uri.path, 'wibble.wobble/foo/bar/quux.pb.dart');
       });
@@ -192,7 +198,7 @@
       test('should throw if target is in unknown package', () {
         var target = Uri.parse('flob/flub/quux.proto');
         var source = Uri.parse('foo/bar/baz.proto');
-        expect(() => config.resolveImport(target, source), throws);
+        expect(() => config.resolveImport(target, source, '.pb.dart'), throws);
       });
     });
   });
diff --git a/test/file_generator_test.dart b/test/file_generator_test.dart
index a8c98e4..a05a12f 100644
--- a/test/file_generator_test.dart
+++ b/test/file_generator_test.dart
@@ -162,14 +162,25 @@
     expect(writer.toString(), expected);
   });
 
-  test('FileGenerator generates a .pb.dart file for a top-level enum', () {
+  test('FileGenerator generates files for a top-level enum', () {
     // NOTE: Below > 80 cols because it is matching generated code > 80 cols.
+
     String expected = r'''
 ///
 //  Generated code. Do not modify.
 ///
 library test;
 
+export 'test.pbenum.dart';
+
+''';
+
+    String expectedEnum = r'''
+///
+//  Generated code. Do not modify.
+///
+library test_pbenum;
+
 import 'package:protobuf/protobuf.dart';
 
 class PhoneType extends ProtobufEnum {
@@ -195,6 +206,7 @@
 }
 
 ''';
+
     FileDescriptorProto fd =
         buildFileDescriptor(phoneNumber: false, topLevelEnum: true);
     var options = parseGenerationOptions(
@@ -206,6 +218,10 @@
     var writer = new IndentingWriter();
     fg.generate(writer);
     expect(writer.toString(), expected);
+
+    writer = new IndentingWriter();
+    fg.generateEnumFile(writer);
+    expect(writer.toString(), expectedEnum);
   });
 
   test('FileGenerator generates a .pbjson.dart file for a top-level enum', () {
@@ -308,6 +324,7 @@
 import 'package:protobuf/protobuf.dart';
 
 import 'test.pbjson.dart';
+
 ''';
     FileDescriptorProto fd = new FileDescriptorProto()
       ..name = 'test'
@@ -400,6 +417,7 @@
 library test;
 
 import 'package:protobuf/protobuf.dart';
+
 import 'package1.pb.dart' as p1;
 import 'package2.pb.dart' as p2;
 
diff --git a/test/message_generator_test.dart b/test/message_generator_test.dart
index 7b7eaa4..9cb0a33 100755
--- a/test/message_generator_test.dart
+++ b/test/message_generator_test.dart
@@ -14,7 +14,7 @@
 void main() {
   test('testMessageGenerator', () {
     // NOTE: Below > 80 cols because it is matching generated code > 80 cols.
-    String expected = r'''
+    String expectedEnums = r'''
 class PhoneNumber_PhoneType extends ProtobufEnum {
   static const PhoneNumber_PhoneType MOBILE = const PhoneNumber_PhoneType._(0, 'MOBILE');
   static const PhoneNumber_PhoneType HOME = const PhoneNumber_PhoneType._(1, 'HOME');
@@ -37,6 +37,9 @@
   const PhoneNumber_PhoneType._(int v, String n) : super(v, n);
 }
 
+''';
+
+    String expected = r'''
 class PhoneNumber extends GeneratedMessage {
   static final BuilderInfo _i = new BuilderInfo('PhoneNumber')
     ..a/*<String>*/(1, 'number', PbFieldType.QS)
@@ -133,5 +136,9 @@
     var writer = new IndentingWriter();
     mg.generate(writer);
     expect(writer.toString(), expected);
+
+    writer = new IndentingWriter();
+    mg.generateEnums(writer);
+    expect(writer.toString(), expectedEnums);
   });
 }