diff --git a/python/jupyter_leaflet/pyproject.toml b/python/jupyter_leaflet/pyproject.toml
index 13b79087..05d1ee05 100644
--- a/python/jupyter_leaflet/pyproject.toml
+++ b/python/jupyter_leaflet/pyproject.toml
@@ -55,6 +55,7 @@ source = "nodejs"
 [tool.hatch.build.targets.sdist]
 exclude = [
     ".github",
+    ".yarn",
 ]
 
 [tool.hatch.build.hooks.jupyter-builder]