diff --git a/install_k8s/install_k8s_ubuntu-final.sh b/install_k8s/install_k8s_ubuntu-final.sh
index 1ce4c91..673b024 100644
--- a/install_k8s/install_k8s_ubuntu-final.sh
+++ b/install_k8s/install_k8s_ubuntu-final.sh
@@ -40,7 +40,7 @@ function prepare_env() {
     systemctl stop ufw 2>/dev/null && systemctl disable ufw 2>/dev/null
 
     swapoff -a
-    sed -i '/ swap / s/^\(.*\)$/#\1/g' /etc/fstab
+    sudo sed -i '/swap/s/^/#/' /etc/fstab
 
     cat <<EOF | tee /etc/modules-load.d/k8s.conf > /dev/null
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