diff --git a/requirements.txt b/requirements.txt
index 21c2652..7157a45 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,5 +4,5 @@ jinja2>=3.1.0
 python-multipart>=0.0.6
 requests>=2.31.0
 azure-identity>=1.15.0
-msgraph-core>=0.2.2
+msgraph-core>=0.2.2,<1.0.0
 apscheduler>=3.10.0