diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2a8e37ba2..953b13fb0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,19 @@
 # Change Log
 
+## [1.2.42](https://github.com/ably/ably-java/tree/v1.2.42)
+
+[Full Changelog](https://github.com/ably/ably-java/compare/v1.2.41...v1.2.42)
+
+**Implemented enhancements:**
+
+-  Implement the `attachOnSubscribe` channel option \(TB4\) [\#1027](https://github.com/ably/ably-java/issues/1027)
+
+**Merged pull requests:**
+
+- Fix implicit attach on subscribe [\#1028](https://github.com/ably/ably-java/pull/1028) ([sacOO7](https://github.com/sacOO7))
+- ci: enable workflow\_dispatch [\#1025](https://github.com/ably/ably-java/pull/1025) ([owenpearson](https://github.com/owenpearson))
+- tests: Assert connection error code rather than message [\#1023](https://github.com/ably/ably-java/pull/1023) ([lmars](https://github.com/lmars))
+
 ## [1.2.41](https://github.com/ably/ably-java/tree/v1.2.41)
 
 [Full Changelog](https://github.com/ably/ably-java/compare/v1.2.40...v1.2.41)
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f5bc814d8..b98399897 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -191,7 +191,7 @@ You may wish to make changes to Ably Java or Ably Android, and test it immediate
 - Open the directory printed from the output of that command. Inside that folder, get the `ably-android-x.y.z.aar`, and place it your Android project's `libs/` directory. Create this directory if it doesn't exist.
 - Add an `implementation` dependency on the `.aar`:
 ```groovy
-implementation files('libs/ably-android-1.2.41.aar')
+implementation files('libs/ably-android-1.2.42.aar')
 ```
 - Add the `implementation` (not `testImplementation`) dependencies found in `dependencies.gradle` to your project. This is because the `.aar` does not contain dependencies.
 - Build/run your application.
diff --git a/README.md b/README.md
index b68ab4531..69ea2b260 100644
--- a/README.md
+++ b/README.md
@@ -20,13 +20,13 @@ Include the library by adding an `implementation` reference to `dependencies` bl
 For [Java](https://mvnrepository.com/artifact/io.ably/ably-java/latest):
 
 ```groovy
-implementation 'io.ably:ably-java:1.2.41'
+implementation 'io.ably:ably-java:1.2.42'
 ```
 
 For [Android](https://mvnrepository.com/artifact/io.ably/ably-android/latest):
 
 ```groovy
-implementation 'io.ably:ably-android:1.2.41'
+implementation 'io.ably:ably-android:1.2.42'
 ```
 
 The library is hosted on [Maven Central](https://mvnrepository.com/repos/central), so you need to ensure that the repository is referenced also; IDEs will typically include this by default:
diff --git a/android/build.gradle b/android/build.gradle
index b6e4c5020..c422c3373 100644
--- a/android/build.gradle
+++ b/android/build.gradle
@@ -31,7 +31,7 @@ android {
         minSdkVersion 19
         targetSdkVersion 30
         // This MUST be incremented by 1 on each ably-java release
-        versionCode 16
+        versionCode 17
         versionName version
         setProperty('archivesBaseName', "ably-android-$versionName")
         testInstrumentationRunner 'android.support.test.runner.AndroidJUnitRunner'
diff --git a/common.gradle b/common.gradle
index 609594af4..7d98567bd 100644
--- a/common.gradle
+++ b/common.gradle
@@ -3,7 +3,7 @@ repositories {
 }
 
 group = 'io.ably'
-version = '1.2.41'
+version = '1.2.42'
 description = 'Ably java client library'
 
 tasks.withType(Javadoc) {
diff --git a/lib/src/test/java/io/ably/lib/test/realtime/RealtimeHttpHeaderTest.java b/lib/src/test/java/io/ably/lib/test/realtime/RealtimeHttpHeaderTest.java
index c259c687c..85d897bd3 100644
--- a/lib/src/test/java/io/ably/lib/test/realtime/RealtimeHttpHeaderTest.java
+++ b/lib/src/test/java/io/ably/lib/test/realtime/RealtimeHttpHeaderTest.java
@@ -88,7 +88,7 @@ public void realtime_websocket_param_test() {
              * Defaults.ABLY_AGENT_PARAM, as ultimately the request param has been derived from those values.
              */
             assertEquals("Verify correct lib version", requestParameters.get("agent"),
-                    Collections.singletonList("ably-java/1.2.41 jre/" + System.getProperty("java.version")));
+                    Collections.singletonList("ably-java/1.2.42 jre/" + System.getProperty("java.version")));
 
             /* Spec RTN2a */
             assertEquals("Verify correct format", requestParameters.get("format"),