diff --git a/kubernetes/k8s-setup-ubuntu.sh b/kubernetes/k8s-setup-ubuntu.sh
index 055e0c6c721a41dd1f9c04c695a13d36f5fa0053..8ed105878c1f1b24973b9c6e2c69acca98687099 100644
--- a/kubernetes/k8s-setup-ubuntu.sh
+++ b/kubernetes/k8s-setup-ubuntu.sh
@@ -23,6 +23,8 @@ EOF
 curl https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
 add-apt-repository "deb [arch=amd64] https://apt.kubernetes.io/ kubernetes-xenial main"
 
+# compatible versions of cluster needed!
+# apt-get install kubeadm=1.18.15-00 kubelet=1.18.15-00 kubectl=1.18.15-00
 apt-get install -y kubelet kubeadm kubectl
 apt-mark hold kubelet kubeadm kubectl