diff --git a/app/main.py b/app/main.py
index b9fdb6f..ac00a7d 100644
--- a/app/main.py
+++ b/app/main.py
@@ -88,8 +88,13 @@
 app.include_router(converter.router)
 app.include_router(predict.router)
 
-app.add_event_handler("startup", tasks.create_start_app_handler(app))
-app.add_event_handler("shutdown", tasks.create_stop_app_handler(app))
+if hasattr(app, "add_event_handler"):
+    app.add_event_handler("startup", tasks.create_start_app_handler(app))
+    app.add_event_handler("shutdown", tasks.create_stop_app_handler(app))
+else:
+    # FastAPI versions that removed direct event registration still support router-level handlers.
+    app.router.add_event_handler("startup", tasks.create_start_app_handler(app))
+    app.router.add_event_handler("shutdown", tasks.create_stop_app_handler(app))
 
 app = VersionedFastAPI(
     app,
diff --git a/requirements.txt b/requirements.txt
index 9e5b55e..547482a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,7 @@
-fastapi
+fastapi<0.116
 uvicorn
 pydantic
+numpy<2
 rdkit-pypi>=2022.09.4
 HOSE_code_generator @ git+https://github.com/Ratsemaat/HOSE_code_generator
 jpype1==1.4.1