diff --git a/nixos/tests/misc.nix b/nixos/tests/misc.nix
index cd4086cb8f6..0efa7282368 100644
--- a/nixos/tests/misc.nix
+++ b/nixos/tests/misc.nix
@@ -122,7 +122,7 @@ import ./make-test.nix ({ pkgs, ...} : {
 
       # Test hidepid
       subtest "hidepid", sub {
-          $machine->succeed("grep -Fq hidepid=2 /etc/mtab");
+          $machine->succeed("grep -Fq hidepid=2 /proc/mounts");
           $machine->succeed("[ `su - sybil -c 'pgrep -c -u root'` = 0 ]");
           $machine->succeed("[ `su - alice -c 'pgrep -c -u root'` != 0 ]");
       };