diff --git a/analysis_options.yaml b/analysis_options.yaml
index 02f94ca6d7..69b3fabcbc 100644
--- a/analysis_options.yaml
+++ b/analysis_options.yaml
@@ -38,7 +38,7 @@ linter:
     - always_specify_types
     - annotate_overrides
     # - avoid_annotating_with_dynamic # conflicts with always_specify_types
-    # - avoid_as # conflicts with NNBD
+    # - avoid_as # no longer relevant with null safety
     - avoid_bool_literals_in_conditional_expressions
     # - avoid_catches_without_on_clauses # we do this commonly
     # - avoid_catching_errors # we do this commonly
diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index dd12d1e06c..afecc10659 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 0.1.19
+
+* Fixed a bug introduced in 0.1.17 where methods without arguments were
+  no longer being called.
+
 ## 0.1.18
 
 * Null safe requires Dart 2.12.
diff --git a/packages/pigeon/lib/dart_generator.dart b/packages/pigeon/lib/dart_generator.dart
index ac4333e48a..1e3acb4b55 100644
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@@ -88,6 +88,7 @@ void _writeFlutterApi(
 }) {
   assert(api.location == ApiLocation.flutter);
   final String nullTag = opt.isNullSafe ? '?' : '';
+  final String unwrapOperator = opt.isNullSafe ? '!' : '';
   indent.write('abstract class ${api.name} ');
   indent.scoped('{', '}', () {
     for (Method func in api.methods) {
@@ -106,10 +107,10 @@ void _writeFlutterApi(
           indent.writeln(
             'const BasicMessageChannel<Object$nullTag> channel =',
           );
+          final String channelName = channelNameFunc == null
+              ? makeChannelName(api, func)
+              : channelNameFunc(func);
           indent.nest(2, () {
-            final String channelName = channelNameFunc == null
-                ? makeChannelName(api, func)
-                : channelNameFunc(func);
             indent.writeln(
               'BasicMessageChannel<Object$nullTag>(\'$channelName\', StandardMessageCodec());',
             );
@@ -134,16 +135,16 @@ void _writeFlutterApi(
                   : func.returnType == 'void'
                       ? 'return;'
                       : 'return null;';
-              indent.write('if (message == null) ');
-              indent.scoped('{', '}', () {
-                indent.writeln(emptyReturnStatement);
-              });
               String call;
               if (argType == 'void') {
+                indent.writeln('// ignore message');
                 call = 'api.${func.name}()';
               } else {
                 indent.writeln(
-                  'final $argType input = $argType.decode(message);',
+                  'assert(message != null, \'Argument for $channelName was null. Expected $argType.\');',
+                );
+                indent.writeln(
+                  'final $argType input = $argType.decode(message$unwrapOperator);',
                 );
                 call = 'api.${func.name}(input)';
               }
@@ -213,7 +214,6 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
       if (klass.fields.isNotEmpty) {
         indent.writeln('');
       }
-      indent.writeln('// ignore: unused_element');
       indent.write('Object encode() ');
       indent.scoped('{', '}', () {
         indent.writeln(
@@ -232,7 +232,6 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
         indent.writeln('return pigeonMap;');
       });
       indent.writeln('');
-      indent.writeln('// ignore: unused_element');
       indent.write(
         'static ${klass.name} decode(Object message) ',
       );
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index bbb76e2b74..0e948a2eaa 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -7,8 +7,8 @@ import 'dart:io';
 import 'dart:mirrors';
 import 'ast.dart';
 
-/// The current version of pigeon.
-const String pigeonVersion = '0.1.18';
+/// The current version of pigeon. This must match the version in pubspec.yaml.
+const String pigeonVersion = '0.1.19';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
diff --git a/packages/pigeon/mock_handler_tester/test/message.dart b/packages/pigeon/mock_handler_tester/test/message.dart
index 2b051a3e97..b7b97ff0c3 100644
--- a/packages/pigeon/mock_handler_tester/test/message.dart
+++ b/packages/pigeon/mock_handler_tester/test/message.dart
@@ -1,16 +1,16 @@
-// Autogenerated from Pigeon (v0.1.15), do not edit directly.
+// Autogenerated from Pigeon (v0.1.19), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import
 // @dart = 2.8
 import 'dart:async';
 import 'dart:typed_data' show Uint8List, Int32List, Int64List, Float64List;
+
 import 'package:flutter/services.dart';
 
 class SearchReply {
   String result;
   String error;
 
-  // ignore: unused_element
   Object encode() {
     final Map<Object, Object> pigeonMap = <Object, Object>{};
     pigeonMap['result'] = result;
@@ -18,7 +18,6 @@ class SearchReply {
     return pigeonMap;
   }
 
-  // ignore: unused_element
   static SearchReply decode(Object message) {
     final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
     return SearchReply()
@@ -32,7 +31,6 @@ class SearchRequest {
   int anInt;
   bool aBool;
 
-  // ignore: unused_element
   Object encode() {
     final Map<Object, Object> pigeonMap = <Object, Object>{};
     pigeonMap['query'] = query;
@@ -41,7 +39,6 @@ class SearchRequest {
     return pigeonMap;
   }
 
-  // ignore: unused_element
   static SearchRequest decode(Object message) {
     final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
     return SearchRequest()
@@ -54,14 +51,12 @@ class SearchRequest {
 class Nested {
   SearchRequest request;
 
-  // ignore: unused_element
   Object encode() {
     final Map<Object, Object> pigeonMap = <Object, Object>{};
     pigeonMap['request'] = request == null ? null : request.encode();
     return pigeonMap;
   }
 
-  // ignore: unused_element
   static Nested decode(Object message) {
     final Map<Object, Object> pigeonMap = message as Map<Object, Object>;
     return Nested()
@@ -81,9 +76,8 @@ abstract class FlutterSearchApi {
         channel.setMessageHandler(null);
       } else {
         channel.setMessageHandler((Object message) async {
-          if (message == null) {
-            return null;
-          }
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.FlutterSearchApi.search was null. Expected SearchRequest.');
           final SearchRequest input = SearchRequest.decode(message);
           final SearchReply output = api.search(input);
           return output.encode();
@@ -121,6 +115,30 @@ class NestedApi {
 }
 
 class Api {
+  Future<void> initialize() async {
+    const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+        'dev.flutter.pigeon.Api.initialize', StandardMessageCodec());
+    final Map<Object, Object> replyMap =
+        await channel.send(null) as Map<Object, Object>;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+        details: null,
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object, Object> error =
+          replyMap['error'] as Map<Object, Object>;
+      throw PlatformException(
+        code: error['code'] as String,
+        message: error['message'] as String,
+        details: error['details'],
+      );
+    } else {
+      // noop
+    }
+  }
+
   Future<SearchReply> search(SearchRequest arg) async {
     final Object encoded = arg.encode();
     const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
diff --git a/packages/pigeon/mock_handler_tester/test/test.dart b/packages/pigeon/mock_handler_tester/test/test.dart
index c2dc28e798..7c6ccf03de 100644
--- a/packages/pigeon/mock_handler_tester/test/test.dart
+++ b/packages/pigeon/mock_handler_tester/test/test.dart
@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v0.1.15), do not edit directly.
+// Autogenerated from Pigeon (v0.1.19), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 // ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import
 // @dart = 2.8
@@ -19,9 +19,8 @@ abstract class TestNestedApi {
         channel.setMockMessageHandler(null);
       } else {
         channel.setMockMessageHandler((Object message) async {
-          if (message == null) {
-            return <Object, Object>{};
-          }
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.NestedApi.search was null. Expected Nested.');
           final Nested input = Nested.decode(message);
           final SearchReply output = api.search(input);
           return <Object, Object>{'result': output.encode()};
@@ -32,8 +31,22 @@ abstract class TestNestedApi {
 }
 
 abstract class TestHostApi {
+  void initialize();
   SearchReply search(SearchRequest arg);
   static void setup(TestHostApi api) {
+    {
+      const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
+          'dev.flutter.pigeon.Api.initialize', StandardMessageCodec());
+      if (api == null) {
+        channel.setMockMessageHandler(null);
+      } else {
+        channel.setMockMessageHandler((Object message) async {
+          // ignore message
+          api.initialize();
+          return <Object, Object>{};
+        });
+      }
+    }
     {
       const BasicMessageChannel<Object> channel = BasicMessageChannel<Object>(
           'dev.flutter.pigeon.Api.search', StandardMessageCodec());
@@ -41,9 +54,8 @@ abstract class TestHostApi {
         channel.setMockMessageHandler(null);
       } else {
         channel.setMockMessageHandler((Object message) async {
-          if (message == null) {
-            return <Object, Object>{};
-          }
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.Api.search was null. Expected SearchRequest.');
           final SearchRequest input = SearchRequest.decode(message);
           final SearchReply output = api.search(input);
           return <Object, Object>{'result': output.encode()};
diff --git a/packages/pigeon/mock_handler_tester/test/widget_test.dart b/packages/pigeon/mock_handler_tester/test/widget_test.dart
index 7fba290235..4f6497c45b 100644
--- a/packages/pigeon/mock_handler_tester/test/widget_test.dart
+++ b/packages/pigeon/mock_handler_tester/test/widget_test.dart
@@ -2,16 +2,25 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:io';
+
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import 'message.dart';
 import 'test.dart';
 
 class Mock implements TestHostApi {
-  bool didCall = false;
+  List<String> log = <String>[];
+
+  @override
+  void initialize() {
+    log.add('initialize');
+  }
+
   @override
   SearchReply search(SearchRequest arg) {
-    didCall = true;
+    log.add('search');
     return SearchReply()..result = arg.query;
   }
 }
@@ -46,7 +55,48 @@ void main() {
     final Mock mock = Mock();
     TestHostApi.setup(mock);
     final SearchReply reply = await api.search(SearchRequest()..query = 'foo');
-    expect(mock.didCall, true);
+    expect(mock.log, <String>['search']);
     expect(reply.result, 'foo');
   });
+
+  test('no-arg calls', () async {
+    final Api api = Api();
+    final Mock mock = Mock();
+    TestHostApi.setup(mock);
+    await api.initialize();
+    expect(mock.log, <String>['initialize']);
+  });
+
+  test(
+    'calling methods with null',
+    () async {
+      final Mock mock = Mock();
+      TestHostApi.setup(mock);
+      expect(
+        await const BasicMessageChannel<Object>(
+          'dev.flutter.pigeon.Api.initialize',
+          StandardMessageCodec(),
+        ).send(null),
+        isEmpty,
+      );
+      try {
+        await const BasicMessageChannel<Object>(
+          'dev.flutter.pigeon.Api.search',
+          StandardMessageCodec(),
+        ).send(null) as Map<Object, Object>;
+        expect(true, isFalse); // should not reach here
+      } catch (error) {
+        expect(error, isAssertionError);
+        expect(
+          error.toString(),
+          contains(
+            'Argument for dev.flutter.pigeon.Api.search was null. Expected SearchRequest.',
+          ),
+        );
+      }
+      expect(mock.log, <String>['initialize']);
+    },
+    // TODO(ianh): skip can be removed after first stable release in 2021
+    skip: Platform.environment['CHANNEL'] == 'stable',
+  );
 }
diff --git a/packages/pigeon/pigeons/message.dart b/packages/pigeon/pigeons/message.dart
index 2dff2f090e..02b95840f6 100644
--- a/packages/pigeon/pigeons/message.dart
+++ b/packages/pigeon/pigeons/message.dart
@@ -20,6 +20,7 @@ class SearchReply {
 
 @HostApi(dartHostTestHandler: 'TestHostApi')
 abstract class Api {
+  void initialize();
   SearchReply search(SearchRequest request);
 }
 
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index 3d2425bc6a..1fd88de9f9 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -1,5 +1,5 @@
 name: pigeon
-version: 0.1.18
+version: 0.1.19 # This must match the version in lib/generator_tools.dart
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 homepage: https://github.com/flutter/packages/tree/master/packages/pigeon
 dependencies:
diff --git a/packages/pigeon/test/dart_generator_test.dart b/packages/pigeon/test/dart_generator_test.dart
index 075e575bc6..2192a9a8ca 100644
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@@ -144,7 +144,10 @@ void main() {
     final StringBuffer sink = StringBuffer();
     generateDart(DartOptions(), root, sink);
     final String code = sink.toString();
-    expect(code, isNot(matches('=.*doSomething')));
+    // The next line verifies that we're not setting a variable to the value of "doSomething", but
+    // ignores the line where we assert the value of the argument isn't null, since on that line
+    // we mention "doSomething" in the assertion message.
+    expect(code, isNot(matches('[^!]=.*doSomething')));
     expect(code, contains('doSomething('));
     expect(code, isNot(contains('.encode()')));
   });
diff --git a/packages/pigeon/test/version_test.dart b/packages/pigeon/test/version_test.dart
index 70e4382a12..d8c867b509 100644
--- a/packages/pigeon/test/version_test.dart
+++ b/packages/pigeon/test/version_test.dart
@@ -11,7 +11,7 @@ void main() {
   test('pigeon version matches pubspec', () {
     final String pubspecPath = '${Directory.current.path}/pubspec.yaml';
     final String pubspec = File(pubspecPath).readAsStringSync();
-    final RegExp regex = RegExp('version:\s*(.*)');
+    final RegExp regex = RegExp('version:\s*(.*?) #');
     final RegExpMatch match = regex.firstMatch(pubspec);
     expect(match, isNotNull);
     expect(pigeonVersion, match.group(1).trim());