diff --git a/build/hydra.nix b/build/hydra.nix
index 98054873d..bc2bb3b52 100644
--- a/build/hydra.nix
+++ b/build/hydra.nix
@@ -2,16 +2,36 @@
 , binaryTarball
 , forAllCrossSystems
 , forAllSystems
-, installScriptFor
 , lib
 , linux64BitSystems
 , nixpkgsFor
 , self
-, testNixVersions
 }:
 let
   inherit (inputs) nixpkgs nixpkgs-regression;
   inherit (lib) fileset;
+
+  installScriptFor = tarballs:
+    nixpkgsFor.x86_64-linux.native.callPackage ./scripts/installer.nix {
+      inherit tarballs;
+    };
+
+  testNixVersions = pkgs: client: daemon:
+    pkgs.callPackage ../package.nix {
+      pname =
+        "nix-tests"
+        + lib.optionalString
+          (lib.versionAtLeast daemon.version "2.4pre20211005" &&
+           lib.versionAtLeast client.version "2.4pre20211005")
+          "-${client.version}-against-${daemon.version}";
+
+      inherit fileset;
+
+      test-client = client;
+      test-daemon = daemon;
+
+      doBuild = false;
+    };
 in
 {
   hydraJobs = {
@@ -96,14 +116,14 @@ in
     };
 
     # API docs for Nix's unstable internal C++ interfaces.
-    internal-api-docs = nixpkgsFor.x86_64-linux.native.callPackage ./package.nix {
+    internal-api-docs = nixpkgsFor.x86_64-linux.native.callPackage ../package.nix {
       inherit fileset;
       doBuild = false;
       enableInternalAPIDocs = true;
     };
 
     # API docs for Nix's C bindings.
-    external-api-docs = nixpkgsFor.x86_64-linux.native.callPackage ./package.nix {
+    external-api-docs = nixpkgsFor.x86_64-linux.native.callPackage ../package.nix {
       inherit fileset;
       doBuild = false;
       enableExternalAPIDocs = true;
diff --git a/flake.nix b/flake.nix
index 866dab00e..a57031cfc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -104,28 +104,6 @@
           cross = forAllCrossSystems (crossSystem: make-pkgs crossSystem "stdenv");
         });
 
-      installScriptFor = tarballs:
-        nixpkgsFor.x86_64-linux.native.callPackage ./scripts/installer.nix {
-          inherit tarballs;
-        };
-
-      testNixVersions = pkgs: client: daemon:
-        pkgs.callPackage ./package.nix {
-          pname =
-            "nix-tests"
-            + lib.optionalString
-              (lib.versionAtLeast daemon.version "2.4pre20211005" &&
-               lib.versionAtLeast client.version "2.4pre20211005")
-              "-${client.version}-against-${daemon.version}";
-
-          inherit fileset;
-
-          test-client = client;
-          test-daemon = daemon;
-
-          doBuild = false;
-        };
-
       binaryTarball = nix: pkgs: pkgs.callPackage ./scripts/binary-tarball.nix {
         inherit nix;
       };
@@ -238,12 +216,10 @@
           binaryTarball
           forAllCrossSystems
           forAllSystems
-          installScriptFor
           lib
           linux64BitSystems
           nixpkgsFor
           self
-          testNixVersions
           ;
         }) hydraJobs;