diff --git a/nixos/modules/monitoring/vpn/server.nix b/nixos/modules/monitoring/vpn/server.nix
index 29430ca0b24d13723b27b23d08bee6ca8bb92a9b..358ca0b0228b8833a34dccbfefbc95798aac514e 100644
--- a/nixos/modules/monitoring/vpn/server.nix
+++ b/nixos/modules/monitoring/vpn/server.nix
@@ -4,7 +4,7 @@
   cfg = config.services.private-storage.monitoring.vpn;
   makePeers = peerIPs: pubKeysPath: map (x: {
                   allowedIPs = [ "${x}/32" ];
-                  publicKey = builtins.readFile(pubKeysPath + "/${x}.pub");
+                  publicKey = lib.fileContents(pubKeysPath + "/${x}.pub");
                   presharedKeyFile = toString cfg.server.presharedKeyFile;
                 }) peerIPs;