diff --git a/CHANGELOG b/CHANGELOG
index ed87306c..1f300f94 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,10 +1,13 @@
-FUTURE
+19-06-2023
+
+- Version 4.3.3
 
   - FIX: Use lowercase header names in `MessageBus::Rack::Middleware` for compatibility with Rack 3.x.
+  - FIX: Don't error when trying to write a message to a closed client
 
 13-01-2023
 
-- Version 4.2.1
+- Version 4.3.2
 
   - FIX: Do not disable chunking on cancel/error
 
@@ -35,7 +38,7 @@ FUTURE
 
   - PERF: Optimize Client#backlog for up-to-date clients
 
-    Also introduces a new MessageBus#last_ids(*channels) api for fetching the last_ids of
+    Also introduces a new MessageBus#last_ids(\*channels) api for fetching the last_ids of
     multiple channels simultaneously
 
 11-01-2022
diff --git a/lib/message_bus/client.rb b/lib/message_bus/client.rb
index 8ef27509..50463fb9 100644
--- a/lib/message_bus/client.rb
+++ b/lib/message_bus/client.rb
@@ -278,7 +278,7 @@ def write_chunk(data)
       @async_response << data
       @async_response << postfix
       @async_response << NEWLINE
-    else
+    elsif @io
       @io.write(chunk_length.to_s(16) << NEWLINE << data << postfix << NEWLINE)
     end
   end
diff --git a/lib/message_bus/version.rb b/lib/message_bus/version.rb
index 46799c5b..a18cf7e1 100644
--- a/lib/message_bus/version.rb
+++ b/lib/message_bus/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module MessageBus
-  VERSION = "4.3.2"
+  VERSION = "4.3.3"
 end
diff --git a/spec/lib/message_bus/client_spec.rb b/spec/lib/message_bus/client_spec.rb
index 139b7331..12c30f05 100644
--- a/spec/lib/message_bus/client_spec.rb
+++ b/spec/lib/message_bus/client_spec.rb
@@ -99,6 +99,12 @@ def parse_chunk(data)
       chunk2.length.must_equal 0
     end
 
+    it "does not raise an error when trying to write a message to a closed client using chunked encoding" do
+      @client.use_chunked = true
+      assert(@client.closed?)
+      @client << MessageBus::Message.new(1, 1, "/test", "test")
+    end
+
     it "does not bleed data across sites" do
       @client.site_id = "test"