diff --git a/hosts/FredOS-Mediaserver.nix b/hosts/FredOS-Mediaserver.nix
index f161a35..3f6a48b 100644
--- a/hosts/FredOS-Mediaserver.nix
+++ b/hosts/FredOS-Mediaserver.nix
@@ -13,11 +13,20 @@
     nix.settings.cores = 8;
     nix.daemonCPUSchedPolicy = "batch";
     systemd.services.nix-daemon.serviceConfig = {
-      MemoryHigh = "12G";
-      MemoryMax = "16G";
+      MemoryHigh = "8G";
+      MemoryMax = "10G";
       OOMPolicy = "continue"; # a killed build shouldn't stop the daemon
     };
 
+    # System-wide backstop for whatever else runs away. oomd was running but
+    # monitoring nothing; now it kills the worst cgroup once memory stalls
+    # hit 80% for 30s (start of a thrash, not 10h in).
+    systemd.oomd.enableRootSlice = true;
+    systemd.oomd.enableSystemSlice = true;
+    # Keep 1G truly free (default ~88M) so kernel networking and the watchdog
+    # can still allocate while userspace is squeezed.
+    boot.kernel.sysctl."vm.min_free_kbytes" = 1048576;
+
     # Basic system packages
     environment.systemPackages = with pkgs; [
       mergerfs