diff --git a/tests/nix-copy-closure.nix b/tests/nix-copy-closure.nix
index 0dc147fb3..bb5db7410 100644
--- a/tests/nix-copy-closure.nix
+++ b/tests/nix-copy-closure.nix
@@ -8,11 +8,11 @@ makeTest (let pkgA = pkgs.cowsay; pkgB = pkgs.wget; pkgC = pkgs.hello; in {
 
   nodes =
     { client =
-        { config, pkgs, ... }:
+        { config, lib, pkgs, ... }:
         { virtualisation.writableStore = true;
           virtualisation.pathsInNixDB = [ pkgA ];
           nix.package = nix;
-          nix.binaryCaches = [ ];
+          nix.binaryCaches = lib.mkForce [ ];
         };
 
       server =
diff --git a/tests/remote-builds.nix b/tests/remote-builds.nix
index b867f13b4..18d490830 100644
--- a/tests/remote-builds.nix
+++ b/tests/remote-builds.nix
@@ -40,7 +40,7 @@ in
       builder2 = builder;
 
       client =
-        { config, pkgs, ... }:
+        { config, lib, pkgs, ... }:
         { nix.maxJobs = 0; # force remote building
           nix.distributedBuilds = true;
           nix.buildMachines =
@@ -60,7 +60,7 @@ in
           virtualisation.writableStore = true;
           virtualisation.pathsInNixDB = [ config.system.build.extraUtils ];
           nix.package = nix;
-          nix.binaryCaches = [ ];
+          nix.binaryCaches = lib.mkForce [ ];
           programs.ssh.extraConfig = "ConnectTimeout 30";
         };
     };
diff --git a/tests/setuid.nix b/tests/setuid.nix
index 77e83c8d6..63d3c05cb 100644
--- a/tests/setuid.nix
+++ b/tests/setuid.nix
@@ -10,7 +10,7 @@ makeTest {
     { config, lib, pkgs, ... }:
     { virtualisation.writableStore = true;
       nix.package = nix;
-      nix.binaryCaches = [ ];
+      nix.binaryCaches = lib.mkForce [ ];
       nix.nixPath = [ "nixpkgs=${lib.cleanSource pkgs.path}" ];
       virtualisation.pathsInNixDB = [ pkgs.stdenv pkgs.pkgsi686Linux.stdenv ];
     };