diff --git a/overlays/testing.nix b/overlays/testing.nix
index 7fe8f0ef..e70c5287 100644
--- a/overlays/testing.nix
+++ b/overlays/testing.nix
@@ -9,7 +9,9 @@ let
   haskellBody = name: commandline: ''
     main = do
       (configDir:hostname:args) <-  getArgs
-      paths <- myNixPath $ toText configDir
+      (decodeUtf8 -> homeManagerChannel) <- nix_instantiate "--eval" "-E" ([i|(import ./channels.nix).#{hostname}.home-manager-channel)|] :: String) |> captureTrim
+      (decodeUtf8 -> nixpkgsChannel) <- nix_instantiate "--eval" "-E" ([i|(import ./channels.nix).#{hostname}.nixpkgs-channel)|] :: String) |> captureTrim
+      paths <- aNixPath homeManagerChannel nixpkgsChannel (toText configDir)
       logFile <- mktemp |> captureTrim
       let command = (${commandline}) &!> StdOut &> Append logFile
           failHandler = do
diff --git a/overlays/writeHaskellScript.nix b/overlays/writeHaskellScript.nix
index e75d1d9d..75444569 100644
--- a/overlays/writeHaskellScript.nix
+++ b/overlays/writeHaskellScript.nix
@@ -50,14 +50,18 @@ self: super: {
         escaped <- nix_instantiate ["--eval" :: String, "-E", [i|toString #{expression}|]] |> captureTrim
         pure . Text.dropAround ('"' ==) . decodeUtf8 . trim $ escaped
 
-      myNixPath :: Text -> IO [String]
-      myNixPath path = concat <$> mapM getNivAssign [("home-manager", "${self.home-manager-channel}"),
-                                                     ("nixpkgs", "${self.nixpkgs-channel}"),
-                                                     ("nixos-unstable", "nixos-unstable")]
+      aNixPath :: Text -> Text -> Text -> IO [String]
+      aNixPath homeManagerChannel nixpkgsChannel path = concat <$> mapM getNivAssign
+          [("home-manager", homeManagerChannel),
+           ("nixpkgs", nixpkgsChannel),
+           ("nixos-unstable", "nixos-unstable")]
         where
          tag name str = ["-I", [i|#{name :: Text}=#{str :: Text}|]] :: [String]
          getNivAssign (name, repo) = tag name <$> getNivPath path repo
 
+      myNixPath :: Text -> IO [String]
+      myNixPath = aNixPath "${self.home-manager-channel}" "${self.nixpkgs-channel}"
+
       buildSystemParams :: [String]
       buildSystemParams = ["<nixpkgs/nixos>", "-A", "system"]