diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c453a07..f4c1fdc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -47,7 +47,7 @@ jobs:
         env:
           POSTGRES_PASSWORD: example-password-change-me
       zookeeper1:
-        image: bitnami/zookeeper:3.7.1
+        image: bitnamilegacy/zookeeper:3.9.3 # this is the last build, so we can use legacy version (internal lib uses different one already)
         env:
           ALLOW_ANONYMOUS_LOGIN: "yes"
           JVMFLAGS: "-Xmx512m -Xms64m"
diff --git a/README.md b/README.md
index fd40011..5dd26cd 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,11 @@
+> [!IMPORTANT]
+> **This repository is no longer open source**
+>
+> To better serve Wise business and customer needs, this library is no longer open source and will not receive further public updates. The codebase has moved to our internal systems.
+>
+> **For continued development and access, please refer to the internal repository:**
+> https://github.com/transferwise/tw-tkms-private
+
 # TransferWise Transactional Kafka Message Sender
 
 ![Apache 2](https://img.shields.io/hexpm/l/plug.svg)
diff --git a/demoapp/docker/docker-compose.yml b/demoapp/docker/docker-compose.yml
index d7bdf15..6475f1c 100644
--- a/demoapp/docker/docker-compose.yml
+++ b/demoapp/docker/docker-compose.yml
@@ -2,21 +2,21 @@ version: '3.7'
 
 services:
   zk-service:
-    image: bitnami/zookeeper:3.5.5
+    image: bitnamilegacy/zookeeper:3.9.3 # this is the last build, so we can use legacy version (internal lib uses different one already)
     hostname: zk-service
     ports:
       - "2181:2181"
     environment:
       ALLOW_ANONYMOUS_LOGIN: "yes"
-      JVMFLAGS: -server -Xms25m -Xmx512m -XX:+UseG1GC -Djava.awt.headless=true -XX:MaxMetaspaceExpansion=2M -XX:+TieredCompilation -XX:+HeapDumpOnOutOfMemoryError -XX:GCHeapFreeLimit=5 -XX:GCTimeLimit=90 -noverify -XX:ReservedCodeCacheSize=256m -Djava.security.egd=file:/dev/./urandom -Dcom.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.fastBoot=true -XX:+AggressiveOpts -XX:+UseFastAccessorMethods -Dcom.sun.xml.internal.bind.v2.bytecode.ClassTailor.noOptimize=true -XX:SoftRefLRUPolicyMSPerMB=5 -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -XX:+ExplicitGCInvokesConcurrentAndUnloadsClasses
+      JVMFLAGS: -server -Xms25m -Xmx512m -XX:+UseG1GC -Djava.awt.headless=true -XX:MaxMetaspaceExpansion=2M -XX:+TieredCompilation -XX:+HeapDumpOnOutOfMemoryError -XX:GCHeapFreeLimit=5 -XX:GCTimeLimit=90 -noverify -XX:ReservedCodeCacheSize=256m -Djava.security.egd=file:/dev/./urandom -Dcom.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.fastBoot=true -XX:+AggressiveOpts -Dcom.sun.xml.internal.bind.v2.bytecode.ClassTailor.noOptimize=true -XX:SoftRefLRUPolicyMSPerMB=5 -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20
   kafka-zk:
-    image: bitnami/zookeeper:3.4.14
+    image: bitnamilegacy/zookeeper:3.9.3 # this is the last build, so we can use legacy version (internal lib uses different one already)
     hostname: kafka-zk
     ports:
       - "2183:2181"
     environment:
       ALLOW_ANONYMOUS_LOGIN: "yes"
-      JVMFLAGS: -server -Xms25m -Xmx512m -XX:+UseG1GC -Djava.awt.headless=true -XX:MaxMetaspaceExpansion=2M -XX:+TieredCompilation -XX:+HeapDumpOnOutOfMemoryError -XX:GCHeapFreeLimit=5 -XX:GCTimeLimit=90 -noverify -XX:ReservedCodeCacheSize=256m -Djava.security.egd=file:/dev/./urandom -Dcom.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.fastBoot=true -XX:+AggressiveOpts -XX:+UseFastAccessorMethods -Dcom.sun.xml.internal.bind.v2.bytecode.ClassTailor.noOptimize=true -XX:SoftRefLRUPolicyMSPerMB=5 -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20 -XX:+ExplicitGCInvokesConcurrentAndUnloadsClasses
+      JVMFLAGS: -server -Xms25m -Xmx512m -XX:+UseG1GC -Djava.awt.headless=true -XX:MaxMetaspaceExpansion=2M -XX:+TieredCompilation -XX:+HeapDumpOnOutOfMemoryError -XX:GCHeapFreeLimit=5 -XX:GCTimeLimit=90 -noverify -XX:ReservedCodeCacheSize=256m -Djava.security.egd=file:/dev/./urandom -Dcom.sun.xml.internal.bind.v2.runtime.JAXBContextImpl.fastBoot=true -XX:+AggressiveOpts -Dcom.sun.xml.internal.bind.v2.bytecode.ClassTailor.noOptimize=true -XX:SoftRefLRUPolicyMSPerMB=5 -XX:MinHeapFreeRatio=10 -XX:MaxHeapFreeRatio=20
   kafka:
     image: wurstmeister/kafka:2.12-2.2.0
     depends_on:
diff --git a/tw-tkms-starter/src/test/resources/docker-compose.yml b/tw-tkms-starter/src/test/resources/docker-compose.yml
index 23021f7..3b7a4eb 100644
--- a/tw-tkms-starter/src/test/resources/docker-compose.yml
+++ b/tw-tkms-starter/src/test/resources/docker-compose.yml
@@ -2,7 +2,7 @@ version: '3.7'
 
 services:
   zookeeper:
-    image: bitnami/zookeeper:3.7.1
+    image: bitnamilegacy/zookeeper:3.9.3 # this is the last build, so we can use legacy version (internal lib uses different one already)
     ports:
       - "2181"
     environment: