diff --git a/packages/pigeon/CHANGELOG.md b/packages/pigeon/CHANGELOG.md
index e61cf9d22d..3ac6ce9452 100644
--- a/packages/pigeon/CHANGELOG.md
+++ b/packages/pigeon/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.1.0-experimental.11
+
+* Fixed setting an api to null in Java.
+
 ## 0.1.0-experimental.10
 
 * Added support for void argument functions.
diff --git a/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.h b/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.h
index 91d45fa852..4371da8ba0 100644
--- a/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.h
+++ b/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.h
@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v0.1.0-experimental.10), do not edit directly.
+// Autogenerated from Pigeon (v0.1.0-experimental.11), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 #import <Foundation/Foundation.h>
 @protocol FlutterBinaryMessenger;
diff --git a/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.m b/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.m
index 05c5b17216..bf419cc900 100644
--- a/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.m
+++ b/packages/pigeon/e2e_tests/test_objc/ios/Runner/dartle.m
@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v0.1.0-experimental.10), do not edit directly.
+// Autogenerated from Pigeon (v0.1.0-experimental.11), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 #import "dartle.h"
 #import <Flutter/Flutter.h>
diff --git a/packages/pigeon/e2e_tests/test_objc/lib/dartle.dart b/packages/pigeon/e2e_tests/test_objc/lib/dartle.dart
index cb9f3b9493..f314807227 100644
--- a/packages/pigeon/e2e_tests/test_objc/lib/dartle.dart
+++ b/packages/pigeon/e2e_tests/test_objc/lib/dartle.dart
@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v0.1.0-experimental.10), do not edit directly.
+// Autogenerated from Pigeon (v0.1.0-experimental.11), 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
 import 'dart:async';
diff --git a/packages/pigeon/lib/generator_tools.dart b/packages/pigeon/lib/generator_tools.dart
index 7d5f8d869c..57d8340368 100644
--- a/packages/pigeon/lib/generator_tools.dart
+++ b/packages/pigeon/lib/generator_tools.dart
@@ -8,7 +8,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon.
-const String pigeonVersion = '0.1.0-experimental.10';
+const String pigeonVersion = '0.1.0-experimental.11';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {
@@ -64,11 +64,15 @@ class Indent {
   /// Scoped increase of the ident level.  For the execution of [func] the
   /// indentation will be incremented.
   void scoped(String begin, String end, Function func) {
-    _sink.write(begin + newline);
+    if (begin != null) {
+      _sink.write(begin + newline);
+    }
     inc();
     func();
     dec();
-    _sink.write(str() + end + newline);
+    if (end != null) {
+      _sink.write(str() + end + newline);
+    }
   }
 
   /// Add [str] with indentation and a newline.
diff --git a/packages/pigeon/lib/java_generator.dart b/packages/pigeon/lib/java_generator.dart
index 3cb5c7ee5f..0015bf39d2 100644
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@@ -53,44 +53,50 @@ void _writeHostApi(Indent indent, Api api) {
               'new BasicMessageChannel<Object>(binaryMessenger, "$channelName", new StandardMessageCodec());');
           indent.dec();
           indent.dec();
-          indent.write(
-              'channel.setMessageHandler(new BasicMessageChannel.MessageHandler<Object>() ');
-          indent.scoped('{', '});', () {
+          indent.write('if (api != null) ');
+          indent.scoped('{', '} else {', () {
             indent.write(
-                'public void onMessage(Object message, BasicMessageChannel.Reply<Object> reply) ');
-            indent.scoped('{', '}', () {
-              final String argType = method.argType;
-              final String returnType = method.returnType;
-              String methodArgument;
-              if (argType == 'void') {
-                methodArgument = '';
-              } else {
-                indent.writeln(
-                    '$argType input = $argType.fromMap((HashMap)message);');
-                methodArgument = 'input';
-              }
-              indent.writeln(
-                  'HashMap<String, HashMap> wrapped = new HashMap<String, HashMap>();');
-              indent.write('try ');
+                'channel.setMessageHandler(new BasicMessageChannel.MessageHandler<Object>() ');
+            indent.scoped('{', '});', () {
+              indent.write(
+                  'public void onMessage(Object message, BasicMessageChannel.Reply<Object> reply) ');
               indent.scoped('{', '}', () {
-                final String call = 'api.${method.name}($methodArgument)';
-                if (method.returnType == 'void') {
-                  indent.writeln('$call;');
-                  indent.writeln('wrapped.put("${Keys.result}", null);');
+                final String argType = method.argType;
+                final String returnType = method.returnType;
+                String methodArgument;
+                if (argType == 'void') {
+                  methodArgument = '';
                 } else {
-                  indent.writeln('$returnType output = $call;');
                   indent.writeln(
-                      'wrapped.put("${Keys.result}", output.toMap());');
+                      '$argType input = $argType.fromMap((HashMap)message);');
+                  methodArgument = 'input';
                 }
-              });
-              indent.write('catch (Exception exception) ');
-              indent.scoped('{', '}', () {
                 indent.writeln(
-                    'wrapped.put("${Keys.error}", wrapError(exception));');
+                    'HashMap<String, HashMap> wrapped = new HashMap<String, HashMap>();');
+                indent.write('try ');
+                indent.scoped('{', '}', () {
+                  final String call = 'api.${method.name}($methodArgument)';
+                  if (method.returnType == 'void') {
+                    indent.writeln('$call;');
+                    indent.writeln('wrapped.put("${Keys.result}", null);');
+                  } else {
+                    indent.writeln('$returnType output = $call;');
+                    indent.writeln(
+                        'wrapped.put("${Keys.result}", output.toMap());');
+                  }
+                });
+                indent.write('catch (Exception exception) ');
+                indent.scoped('{', '}', () {
+                  indent.writeln(
+                      'wrapped.put("${Keys.error}", wrapError(exception));');
+                });
+                indent.writeln('reply.reply(wrapped);');
               });
-              indent.writeln('reply.reply(wrapped);');
             });
           });
+          indent.scoped(null, '}', () {
+            indent.writeln('channel.setMessageHandler(null);');
+          });
         });
       }
     });
diff --git a/packages/pigeon/pubspec.yaml b/packages/pigeon/pubspec.yaml
index d529dae9c1..f3c11e9a37 100644
--- a/packages/pigeon/pubspec.yaml
+++ b/packages/pigeon/pubspec.yaml
@@ -1,5 +1,5 @@
 name: pigeon
-version: 0.1.0-experimental.10
+version: 0.1.0-experimental.11
 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/java_generator_test.dart b/packages/pigeon/test/java_generator_test.dart
index 51eef3e186..9113261ad6 100644
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@@ -69,6 +69,7 @@ void main() {
     final String code = sink.toString();
     expect(code, contains('public interface Api'));
     expect(code, matches('Output.*doSomething.*Input'));
+    expect(code, contains('channel.setMessageHandler(null)'));
   });
 
   test('all the simple datatypes header', () {