diff --git a/tests/hermetic.nix b/tests/hermetic.nix
new file mode 100644
index 000000000..7ccd0fd72
--- /dev/null
+++ b/tests/hermetic.nix
@@ -0,0 +1,56 @@
+{ busybox }:
+
+with import ./config.nix;
+
+let
+  contentAddressedByDefault = builtins.getEnv "NIX_TESTS_CA_BY_DEFAULT" == "1";
+  caArgs = if contentAddressedByDefault then {
+    __contentAddressed = true;
+    outputHashMode = "recursive";
+    outputHashAlgo = "sha256";
+  } else {};
+
+  mkDerivation = args:
+    derivation ({
+      inherit system;
+      builder = busybox;
+      args = ["sh" "-e" args.builder or (builtins.toFile "builder-${args.name}.sh" "if [ -e .attrs.sh ]; then source .attrs.sh; fi; eval \"$buildCommand\"")];
+    } // removeAttrs args ["builder" "meta" "passthru"]
+    // caArgs)
+    // { meta = args.meta or {}; passthru = args.passthru or {}; };
+
+  input1 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-1";
+    buildCommand = "echo hi-input1; echo FOO > $out";
+  };
+
+  input2 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-2";
+    buildCommand = "echo hi; echo BAR > $out";
+  };
+
+  input3 = mkDerivation {
+    shell = busybox;
+    name = "build-remote-input-3";
+    buildCommand = ''
+      echo hi-input3
+      read x < ${input2}
+      echo $x BAZ > $out
+    '';
+  };
+
+in
+
+  mkDerivation {
+    shell = busybox;
+    name = "build-remote";
+    passthru = { inherit input1 input2 input3; };
+    buildCommand =
+      ''
+        read x < ${input1}
+        read y < ${input3}
+        echo "$x $y" > $out
+      '';
+  }
diff --git a/tests/overlay-local-store.sh b/tests/overlay-local-store.sh
index 6c0a5f96d..c98931118 100644
--- a/tests/overlay-local-store.sh
+++ b/tests/overlay-local-store.sh
@@ -1,3 +1,7 @@
 source common.sh
 
+requireSandboxSupport
+[[ $busybox =~ busybox ]] || skipTest "no busybox"
+if [[ $(uname) != Linux ]]; then skipTest "Need Linux for overlayfs"; fi
+
 exec unshare --mount --map-root-user overlay-local-store/inner.sh
diff --git a/tests/overlay-local-store/inner.sh b/tests/overlay-local-store/inner.sh
index fb690a85f..5079dd0bd 100755
--- a/tests/overlay-local-store/inner.sh
+++ b/tests/overlay-local-store/inner.sh
@@ -11,13 +11,16 @@ export NIX_CONFIG='build-users-group = '
 # Creating testing directories
 
 storeA="$TEST_ROOT/store_a"
-storeB="$TEST_ROOT/store_b?real=$TEST_ROOT/merged-store"
+storeB="local-overlay?root=$TEST_ROOT/store_b&lower-store=$TEST_ROOT/merged-store"
 storeBTop="$TEST_ROOT/store_b"
 
 mkdir -p "$TEST_ROOT"/{store_a,store_b,merged-store,workdir}
 
 # Mounting Overlay Store
 
+## Restore normal, because we are using these chroot stores
+#NIX_STORE_DIR=/nix/store
+
 nix-store --store "$TEST_ROOT/store_a" --add dummy
 nix-store --store "$TEST_ROOT/store_b" --add dummy
 
@@ -27,7 +30,14 @@ mount -t overlay overlay \
   -o workdir="$TEST_ROOT/workdir" \
   "$TEST_ROOT/merged-store" || skipTest "overlayfs is not supported"
 
-path_a=$(nix-build '<nixpkgs>' -A signal-desktop --store "$storeA")
+# Add in lower
+NIX_REMOTE=$storeA source add.sh
+
+# Add in layered
+NIX_REMOTE=$storeB source add.sh
+
+#busyboxExpr="\"\${$(dirname "$busybox")}/$(basename "$busybox")\""
+path_a=$(nix-build ./hermetic.nix --arg busybox "$busybox" --store "$storeA")
 
 # Checking for Path in store_a
 stat "$TEST_ROOT/store_a/$path_a"
@@ -48,4 +58,4 @@ expect 1 nix-store --verify-path --store "$storeB" "$path_a"
 # Verifying path in store_b (Should fail)
 expect 1 nix-store --verify-path --store "$storeBTop" "$path_a"
 
-path_b=$(nix-build '<nixpkgs>' -A signal-desktop --store "$storeB")
+path_b=$(nix-build ./hermetic.nix --arg busybox $busybox --store "$storeB")