diff --git a/pyproject.toml b/pyproject.toml
index f010ccc..609dccd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -34,7 +34,7 @@ classifiers = [
 dependencies = [
     "numpy>=1.26",
     "omop-alchemy>=0.5.7",
-    "orm-loader>=0.3.15",
+    "orm-loader>=0.3.27,<0.4.0",
     "sqlalchemy>=2.0.45",
     "typing-extensions>=4.15.0",
     "sqlite-vec>=0.1.9",