diff --git a/pyproject.toml b/pyproject.toml
index c572e81..8a72c29 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -36,7 +36,7 @@ classifiers = [
 
 dependencies = [
   "omop-alchemy>=0.6.0",
-  "orm-loader>=0.3.15",
+  "orm-loader>=0.3.27,<0.4.0",
   "psycopg2-binary>=2.9.11",
   "sqlalchemy>=2.0.45",
   "typing-extensions>=4.15.0",