diff --git a/pyproject.toml b/pyproject.toml
index d69854b..20c55c5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,7 +34,8 @@ dependencies = [
   "pandas",
   "Pillow",
   "scikit-learn",
-  "scipy"
+  "scipy",
+  "pymongo<4.9"  # 4.9 introduced import error
 ]
 dynamic = ["version"]