diff --git a/agents.tf b/agents.tf
index 58f3af5..46a57c0 100644
--- a/agents.tf
+++ b/agents.tf
@@ -59,7 +59,7 @@ resource "hcloud_server" "agents" {
       kubelet-arg   = "cloud-provider=external"
       flannel-iface = "eth1"
       node-ip       = cidrhost(hcloud_network_subnet.k3s.ip_range, 513 + count.index)
-      node-label    = var.automatically_upgrade_k3s ? ["k3s-upgrade=true"] : []
+      node-label    = var.automatically_upgrade_k3s ? ["k3s_upgrade=true"] : []
     })
     destination = "/tmp/config.yaml"
   }
diff --git a/master.tf b/master.tf
index d1ec8b7..19272fd 100644
--- a/master.tf
+++ b/master.tf
@@ -61,7 +61,7 @@ resource "hcloud_server" "first_control_plane" {
       advertise-address        = local.first_control_plane_network_ip
       token                    = random_password.k3s_token.result
       node-taint               = var.allow_scheduling_on_control_plane ? [] : ["node-role.kubernetes.io/master:NoSchedule"]
-      node-label               = var.automatically_upgrade_k3s ? ["k3s-upgrade=true"] : []
+      node-label               = var.automatically_upgrade_k3s ? ["k3s_upgrade=true"] : []
     })
     destination = "/tmp/config.yaml"
   }
diff --git a/servers.tf b/servers.tf
index f85a617..0db1ea5 100644
--- a/servers.tf
+++ b/servers.tf
@@ -64,7 +64,7 @@ resource "hcloud_server" "control_planes" {
       advertise-address        = cidrhost(hcloud_network_subnet.k3s.ip_range, 258 + count.index)
       tls-san                  = cidrhost(hcloud_network_subnet.k3s.ip_range, 258 + count.index)
       node-taint               = var.allow_scheduling_on_control_plane ? [] : ["node-role.kubernetes.io/master:NoSchedule"]
-      node-label               = var.automatically_upgrade_k3s ? ["k3s-upgrade=true"] : []
+      node-label               = var.automatically_upgrade_k3s ? ["k3s_upgrade=true"] : []
     })
     destination = "/tmp/config.yaml"
   }