diff --git a/lib/src/main/java/io/ably/lib/realtime/ChannelBase.java b/lib/src/main/java/io/ably/lib/realtime/ChannelBase.java
index ce15010cc..2ef6a3718 100644
--- a/lib/src/main/java/io/ably/lib/realtime/ChannelBase.java
+++ b/lib/src/main/java/io/ably/lib/realtime/ChannelBase.java
@@ -221,7 +221,7 @@ private void attachImpl(final boolean forceReattach, final CompletionListener li
         if(!forceReattach) {
             /* check preconditions */
             switch(state) {
-                case attaching:
+                case attaching: //RTL4h
                     if(listener != null) {
                         on(new ChannelStateCompletionListener(listener, ChannelState.attached, ChannelState.failed));
                     }
@@ -229,9 +229,11 @@ private void attachImpl(final boolean forceReattach, final CompletionListener li
                 case detaching: //RTL4h
                     pendingAttachRequest = new AttachRequest(forceReattach,listener);
                     return;
-                case attached:
+                case attached: //RTL4a
                     callCompletionListenerSuccess(listener);
                     return;
+                case failed: //RTL4g
+                    this.reason = null;
                 default:
             }
         }
@@ -312,12 +314,12 @@ private void detachImpl(CompletionListener listener) throws AblyException {
         Log.v(TAG, "detach(); channel = " + name);
         /* check preconditions */
         switch(state) {
-            case initialized:
+            case initialized: // RTL5a
             case detached: {
                 callCompletionListenerSuccess(listener);
                 return;
             }
-            case detaching:
+            case detaching: //RTL5i
                 if (listener != null) {
                     on(new ChannelStateCompletionListener(listener, ChannelState.detached, ChannelState.failed));
                 }
@@ -325,6 +327,15 @@ private void detachImpl(CompletionListener listener) throws AblyException {
             case attaching: //RTL5i
                 pendingDetachRequest = new DetachRequest(listener);
                 return;
+            case failed: //RTL5b
+                ErrorInfo error = this.reason != null ?
+                    this.reason : new ErrorInfo("Channel state is failed", 90000);
+                callCompletionListenerError(listener, error);
+                return;
+            case suspended: //RTL5j
+                setState(ChannelState.detached, null);
+                callCompletionListenerSuccess(listener);
+                return;
             default:
         }
         ConnectionManager connectionManager = ably.connection.connectionManager;
diff --git a/lib/src/test/java/io/ably/lib/test/realtime/RealtimeChannelTest.java b/lib/src/test/java/io/ably/lib/test/realtime/RealtimeChannelTest.java
index 3279e8c7b..d60f7179b 100644
--- a/lib/src/test/java/io/ably/lib/test/realtime/RealtimeChannelTest.java
+++ b/lib/src/test/java/io/ably/lib/test/realtime/RealtimeChannelTest.java
@@ -930,7 +930,7 @@ public void attach_success_callback() {
             Helpers.CompletionWaiter waiter = new Helpers.CompletionWaiter();
             channel.attach(waiter);
             new ChannelWaiter(channel).waitFor(ChannelState.attached);
-            assertEquals("Verify failed state reached", channel.state, ChannelState.attached);
+            assertEquals("Verify attached state reached", channel.state, ChannelState.attached);
 
             /* Verify onSuccess callback gets called */
             waiter.waitFor();
@@ -944,6 +944,59 @@ public void attach_success_callback() {
         }
     }
 
+    @Test
+    public void attach_success_callback_for_channel_in_failed_state() {
+        AblyRealtime ably = null;
+        try {
+            ClientOptions opts = createOptions(testVars.keys[0].keyStr);
+            ably = new AblyRealtime(opts);
+
+            /* wait until connected */
+            (new ConnectionWaiter(ably.connection)).waitFor(ConnectionState.connected);
+
+            /* create a channel and attach */
+            final Channel channel = ably.channels.get("attach_success");
+            ChannelWaiter channelWaiter = new ChannelWaiter(channel);
+            channel.attach();
+            channelWaiter.waitFor(ChannelState.attached);
+
+            // Simulate connection failure
+            ably.connection.connectionManager.requestState(
+                new ConnectionManager.StateIndication(
+                    ConnectionState.failed,
+                    new ErrorInfo("Simulated connection failure", 40000)
+                )
+            );
+
+            // Wait for the channel to reach the failed state
+            channelWaiter.waitFor(ChannelState.failed);
+
+            assertNotNull(channel.reason);
+            assertEquals("Simulated connection failure", channel.reason.message);
+
+            ably.connect();
+
+            Helpers.CompletionWaiter attachListener = new Helpers.CompletionWaiter();
+            channel.attach(attachListener);
+
+            channelWaiter.waitFor(ChannelState.attaching);
+            assertNull(channel.reason);
+            channelWaiter.waitFor(ChannelState.attached);
+
+            assertEquals("Verify attached state reached", ChannelState.attached, channel.state);
+
+            /* Verify onSuccess callback gets called */
+            attachListener.waitFor();
+            assertTrue(attachListener.success);
+        } catch (AblyException e) {
+            e.printStackTrace();
+            fail("init0: Unexpected exception instantiating library");
+        } finally {
+            if(ably != null)
+                ably.close();
+        }
+    }
+
     /**
      * When client failed to attach to a channel, verify
      * attach {@code CompletionListener#onError(ErrorInfo)}
@@ -1015,6 +1068,84 @@ public void detach_success_callback_initialized() {
         }
     }
 
+    @Test
+    public void detach_success_callback_on_suspended_state() {
+        AblyRealtime ably = null;
+        try {
+            ClientOptions opts = createOptions(testVars.keys[0].keyStr);
+            ably = new AblyRealtime(opts);
+
+            /* wait until connected */
+            (new ConnectionWaiter(ably.connection)).waitFor(ConnectionState.connected);
+
+            /* create a channel and attach */
+            final Channel channel = ably.channels.get("detach_success");
+            ChannelWaiter channelWaiter = new ChannelWaiter(channel);
+            channel.attach();
+            channelWaiter.waitFor(ChannelState.attached);
+
+            ably.connection.connectionManager.requestState(ConnectionState.suspended);
+
+            channelWaiter.waitFor(ChannelState.suspended);
+            assertEquals("Verify suspended state reached", ChannelState.suspended, channel.state);
+
+            /* detach */
+            Helpers.CompletionWaiter detachWaiter = new Helpers.CompletionWaiter();
+            channel.detach(detachWaiter);
+
+            /* Verify onSuccess callback gets called */
+            detachWaiter.waitFor();
+            assertTrue(detachWaiter.success);
+        } catch (AblyException e) {
+            e.printStackTrace();
+            fail("init0: Unexpected exception instantiating library");
+        } finally {
+            if(ably != null)
+                ably.close();
+        }
+    }
+
+    @Test
+    public void detach_failure_callback_on_failed_state() {
+        AblyRealtime ably = null;
+        try {
+            ClientOptions opts = createOptions(testVars.keys[0].keyStr);
+            ably = new AblyRealtime(opts);
+
+            /* wait until connected */
+            (new ConnectionWaiter(ably.connection)).waitFor(ConnectionState.connected);
+
+            /* create a channel and attach */
+            final Channel channel = ably.channels.get("detach_failure");
+            ChannelWaiter channelWaiter = new ChannelWaiter(channel);
+            channel.attach();
+            channelWaiter.waitFor(ChannelState.attached);
+
+            // Simulate connection failure
+            ably.connection.connectionManager.requestState(ConnectionState.failed);
+
+            channelWaiter.waitFor(ChannelState.failed);
+            assertEquals("Verify failed state reached", ChannelState.failed, channel.state);
+
+            /* detach */
+            Helpers.CompletionWaiter detachWaiter = new Helpers.CompletionWaiter();
+            channel.detach(detachWaiter);
+
+            /* Verify onSuccess callback gets called */
+            detachWaiter.waitFor();
+            assertFalse(detachWaiter.success);
+            assertNotNull(detachWaiter.error);
+            assertEquals("Channel state is failed", detachWaiter.error.message);
+            assertEquals(90000, detachWaiter.error.code);
+        } catch (AblyException e) {
+            e.printStackTrace();
+            fail("init0: Unexpected exception instantiating library");
+        } finally {
+            if(ably != null)
+                ably.close();
+        }
+    }
+
     /**
      * When client detaches from a channel successfully after attached state,
      * verify attach {@code CompletionListener#onSuccess()} gets called.