diff --git a/packages/py-pythreejs/package.py b/packages/py-pythreejs/package.py
index 25e559dde60450dda78be45d466671cdbb7a832b..a86fc10e6b6e8fd825140393f538134e379e94e7 100644
--- a/packages/py-pythreejs/package.py
+++ b/packages/py-pythreejs/package.py
@@ -35,3 +35,7 @@ class PyPythreejs(PythonPackage):
     depends_on("py-ipywidgets@7.2.1:", type=("build", "run"))
     depends_on("py-ipydatawidgets@1.1.1:", type=("build", "run"))
     depends_on("py-jupyter-core", type=("build", "run"))
+
+    def setup_build_environment(self, env):
+        import os
+        env.set("npm_config_cache", os.path.join(self.stage.path, "npm-cache"))