diff --git a/lib/src/main/java/io/ably/lib/realtime/AblyRealtime.java b/lib/src/main/java/io/ably/lib/realtime/AblyRealtime.java
index 74129ff9d..f22789c78 100644
--- a/lib/src/main/java/io/ably/lib/realtime/AblyRealtime.java
+++ b/lib/src/main/java/io/ably/lib/realtime/AblyRealtime.java
@@ -290,7 +290,9 @@ protected void setChannelSerialsFromRecoverOption(Map<String, String> serials) {
     protected Map<String, String> getChannelSerials() {
         Map<String, String> channelSerials = new HashMap<>();
         for (Channel channel : this.channels.values()) {
-            channelSerials.put(channel.name, channel.properties.channelSerial);
+            if (channel.state == ChannelState.attached) {
+                channelSerials.put(channel.name, channel.properties.channelSerial);
+            }
         }
         return channelSerials;
     }