diff --git a/pyproject.toml b/pyproject.toml
index 179ad722..4a8bd8e5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ description = "Python client library for IBM Cloudant"
 dependencies = [
   "ibm_cloud_sdk_core==3.28.0",
   "requests>=2.32.4,<3.0.0",
-  "python_dateutil>=2.5.3,<3.0.0",
+  "python_dateutil>=2.5.3,<4.0.0",
   "PyJWT>=2.0.1,<3.0.0",
 ]
 authors = [