diff --git a/setup.py b/setup.py
index b1d4a27..efbc8e0 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@
 
 install_requires = [
     'flask>=2.1.2', 'functions-framework>=3.0.0', 'firebase-admin>=6.0.0',
-    'pyyaml>=6.0', 'typing-extensions>=4.4.0', 'cloudevents==1.9.0',
+    'pyyaml>=6.0', 'typing-extensions>=4.4.0', 'cloudevents>=1.2.0,<2.0.0',
     'flask-cors>=3.0.10', 'pyjwt[crypto]>=2.5.0', 'google-events==0.5.0',
     'google-cloud-firestore>=2.11.0'
 ]