diff --git a/agents.tf b/agents.tf
index 8ca5cc7..16f0f05 100644
--- a/agents.tf
+++ b/agents.tf
@@ -27,9 +27,10 @@ resource "hcloud_server" "agents" {
     destination = "/tmp/config.yaml"
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }
 
@@ -38,9 +39,10 @@ resource "hcloud_server" "agents" {
     inline = local.k3os_install_commands
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }
 
diff --git a/master.tf b/master.tf
index 8da0368..ec7cf25 100644
--- a/master.tf
+++ b/master.tf
@@ -23,9 +23,10 @@ resource "hcloud_server" "first_control_plane" {
     destination = "/tmp/config.yaml"
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }
 
@@ -34,9 +35,10 @@ resource "hcloud_server" "first_control_plane" {
     inline = local.k3os_install_commands
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }
 
diff --git a/servers.tf b/servers.tf
index 1510017..bb0cfbb 100644
--- a/servers.tf
+++ b/servers.tf
@@ -26,9 +26,10 @@ resource "hcloud_server" "control_planes" {
     destination = "/tmp/config.yaml"
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }
 
@@ -37,9 +38,10 @@ resource "hcloud_server" "control_planes" {
     inline = local.k3os_install_commands
 
     connection {
-      user        = "root"
-      private_key = file(var.private_key)
-      host        = self.ipv4_address
+      user           = "root"
+      private_key    = var.private_key == null ? null : file(var.private_key)
+      agent_identity = var.private_key == null ? file(var.public_key) : null
+      host           = self.ipv4_address
     }
   }