diff --git a/flake.nix b/flake.nix
index aeea10f9..d0ff0c02 100644
--- a/flake.nix
+++ b/flake.nix
@@ -75,7 +75,7 @@
           pkgs = nixpkgsFor.${system};
           envFor = comp: (pkgs.python2.buildEnv.override {
             extraLibs = [ pkgs.${"coriolis-${comp}"} ];
-          }).env;
+          });
         in builtins.catAttrs (builtins.map (comp: { ${comp} = envFor comp; }) pythonComponents)
       );
       devShell = forAllSystems (system:
diff --git a/nix/crlcore.nix b/nix/crlcore.nix
index 7660f0da..f8a85cc1 100644
--- a/nix/crlcore.nix
+++ b/nix/crlcore.nix
@@ -1,12 +1,20 @@
 { generic, ... }:
 let pkg =
   { libxml2, qt4, bison, flex, doxygen, coriolis-vlsisapd
-  , coriolis-lefdef, coriolis-hurricane }:
+  , coriolis-lefdef, coriolis-hurricane, python2Packages }:
   {
     name = "crlcore";
     src = ../crlcore;
-    buildInputs = [ libxml2 qt4 coriolis-lefdef coriolis-vlsisapd coriolis-hurricane ];
-    nativeBuildInputs = [ bison flex doxygen ];
-    pythonImportsCheck = [ "CRL" "Constant" ];
+    buildInputs = [ libxml2 qt4 coriolis-lefdef coriolis-vlsisapd coriolis-hurricane python2Packages.pyqt4 python2Packages.sip_4 ];
+    nativeBuildInputs = [ bison flex doxygen python2Packages.pyqt4 ];
+    pythonImportsCheck = [
+      "CRL" "Constant" "helpers.io" "helpers.technology"
+      "helpers.utils" "helpers.analogtechno" "helpers" "helpers.overlay"
+    ];
+    continuation = drv: drv.overrideAttrs (o: {
+      postInstall = (o.postInstall or "") + ''
+        ln -s crlcore/helpers $out/${python2Packages.python.sitePackages}/helpers
+      '';
+    });
   };
 in generic pkg
diff --git a/nix/generic.nix b/nix/generic.nix
index 62fcaee9..24ebe73c 100644
--- a/nix/generic.nix
+++ b/nix/generic.nix
@@ -9,6 +9,7 @@ let f =
   , nativeBuildInputs ? []
   , propagatedBuildInputs ? []
   , pythonImportsCheck
+  , continuation ? (x: x)
   }:
   let
     boostWithPython = boost.override { enablePython = true; inherit (python2Packages) python; };
@@ -28,7 +29,7 @@ let f =
 
       inherit version meta src pythonImportsCheck;
     };
-  in python2Packages.toPythonModule drv;
+  in continuation (python2Packages.toPythonModule drv);
 in
 
 pkg: