diff --git a/nixos/modules/testing/test-instrumentation.nix b/nixos/modules/testing/test-instrumentation.nix
index f37bbd0246da..c1dbfe305ddd 100644
--- a/nixos/modules/testing/test-instrumentation.nix
+++ b/nixos/modules/testing/test-instrumentation.nix
@@ -88,6 +88,10 @@ let kernel = config.boot.kernelPackages.kernel; in
 
     boot.consoleLogLevel = 7;
 
+    # Make sure we don't hit page allocation failures if the VM's memory is
+    # heavily fragmented.
+    boot.kernel.sysctl."vm.min_free_kbytes" = 16384;
+
     # Prevent tests from accessing the Internet.
     networking.defaultGateway = mkOverride 150 "";
     networking.nameservers = mkOverride 150 [ ];