diff --git a/nixos/modules/services/networking/murmur.nix b/nixos/modules/services/networking/murmur.nix
index 692868c8a790..c192a8f35231 100644
--- a/nixos/modules/services/networking/murmur.nix
+++ b/nixos/modules/services/networking/murmur.nix
@@ -347,6 +347,7 @@ in
         MemoryDenyWriteExecute = true;
         NoNewPrivileges = true;
         PrivateDevices = true;
+        PrivateMounts = true;
         PrivateTmp = true;
         ProtectClock = true;
         ProtectControlGroups = true;