diff --git a/pkgs/applications/science/electronics/kicad/libraries.nix b/pkgs/applications/science/electronics/kicad/libraries.nix
index 9591cbc31c39..327f77d1c42f 100644
--- a/pkgs/applications/science/electronics/kicad/libraries.nix
+++ b/pkgs/applications/science/electronics/kicad/libraries.nix
@@ -2,6 +2,9 @@
 , cmake
 , gettext
 , libSrc
+, stepreduce
+, parallel
+, zip
 }:
 let
   mkLib = name:
@@ -11,14 +14,20 @@ let
 
       src = libSrc name;
 
-      nativeBuildInputs = [ cmake ];
+      nativeBuildInputs = [ cmake ]
+        ++ lib.optionals (name == "packages3d") [
+          stepreduce
+          parallel
+          zip
+        ];
+
+      postInstall = lib.optional (name == "packages3d") ''
+        find $out -type f -name '*.step' | parallel 'stepreduce {} {} && zip -9 {.}.stpZ {} && rm {}'
+      '';
 
       meta = rec {
         license = lib.licenses.cc-by-sa-40;
         platforms = lib.platforms.all;
-        # the 3d models are a ~1 GiB download and occupy ~5 GiB in store.
-        # this would exceed the hydra output limit
-        hydraPlatforms = if (name == "packages3d") then [ ] else platforms;
       };
     };
 in