diff --git a/pyproject.toml b/pyproject.toml
index 5520928..0a62a4b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,7 +28,7 @@ keywords=["ibm", "cloud", "ibm cloud services"]
 dependencies = [
     "requests>=2.32.4,<3.0.0",
     "urllib3>=2.4.0,<3.0.0",
-    "python_dateutil>=3.0.0,<3.1.0",
+    "python_dateutil>=4.0.0,<4.1.0",
     "PyJWT>=2.11.0,<3.0.0",
 ]