diff --git a/setup.py b/setup.py
index d0d5b45..1fef10d 100644
--- a/setup.py
+++ b/setup.py
@@ -33,7 +33,7 @@
         url=f"https://github.com/ansys/{package_name}",
         license="MIT",
         python_requires=">=3.7",
-        install_requires=["grpcio~=1.17", "protobuf>=3.19,<5"],
+        install_requires=["grpcio~=1.17", "protobuf>=3.19,<6"],
         package_dir={"": "src"},
         packages=setuptools.find_namespace_packages("src", include=("ansys.*",)),
         package_data={