diff --git a/proxmox-zfs-postinstall.sh b/proxmox-zfs-postinstall.sh
index 4086247..7df1062 100644
--- a/proxmox-zfs-postinstall.sh
+++ b/proxmox-zfs-postinstall.sh
@@ -169,7 +169,11 @@ if [[ "$(uname -r)" == *"-pve" ]]; then
     echo "Deactivating pve-enterprise repository"
     mv /etc/apt/sources.list.d/pve-enterprise.list /etc/apt/sources.list.d/pve-enterprise.list.bak > /dev/null 2>&1
     echo "Activating pve-no-subscription repository"
-    echo "deb http://download.proxmox.com/debian/pve $VERSION_CODENAME pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list
+    q=$(cat /etc/apt/sources.list | grep "pve-no-subscription")
+    if [ $? -gt 0 ]; then
+        echo "deb http://download.proxmox.com/debian/pve $VERSION_CODENAME pve-no-subscription" >> /etc/apt/sources.list
+    fi
+    rm -f /etc/apt/sources.list.d/pve-no-subscription.list
 fi
 echo "Getting latest package lists"
 apt update > /dev/null 2>&1