diff --git a/nixos/hosts/frankfurt-linode-01/containers/derp.nix b/nixos/hosts/frankfurt-linode-01/containers/derp.nix
index 9504d639..ebf965c8 100644
--- a/nixos/hosts/frankfurt-linode-01/containers/derp.nix
+++ b/nixos/hosts/frankfurt-linode-01/containers/derp.nix
@@ -16,7 +16,7 @@
       DERP_DOMAIN = "frankfurt.sysctl.io";
       DERP_STUN = "true";
       DERP_VERIFY_CLIENTS = "true";
-      DERP_HTTP_PORT = -1;
+      DERP_HTTP_PORT = "-1";
     };
     volumes = [
       "/var/run/tailscale/tailscaled.sock:/var/run/tailscale/tailscaled.sock:ro"
diff --git a/nixos/hosts/milan-linode-01/containers/derp.nix b/nixos/hosts/milan-linode-01/containers/derp.nix
index 26490e03..3972ac54 100644
--- a/nixos/hosts/milan-linode-01/containers/derp.nix
+++ b/nixos/hosts/milan-linode-01/containers/derp.nix
@@ -16,7 +16,7 @@
       DERP_DOMAIN = "milan.sysctl.io";
       DERP_STUN = "true";
       DERP_VERIFY_CLIENTS = "true";
-      DERP_HTTP_PORT = -1;
+      DERP_HTTP_PORT = "-1";
     };
     volumes = [
       "/var/run/tailscale/tailscaled.sock:/var/run/tailscale/tailscaled.sock:ro"
diff --git a/nixos/hosts/osaka-linode-01/containers/derp.nix b/nixos/hosts/osaka-linode-01/containers/derp.nix
index 5c39dfc5..82ac2bbc 100644
--- a/nixos/hosts/osaka-linode-01/containers/derp.nix
+++ b/nixos/hosts/osaka-linode-01/containers/derp.nix
@@ -16,7 +16,7 @@
       DERP_DOMAIN = "sysctl.io";
       DERP_STUN = "true";
       DERP_VERIFY_CLIENTS = "true";
-      DERP_HTTP_PORT = -1;
+      DERP_HTTP_PORT = "-1";
     };
     volumes = [
       "/var/run/tailscale/tailscaled.sock:/var/run/tailscale/tailscaled.sock:ro"