diff --git a/ci/env/install-core-prerelease-dependencies.sh b/ci/env/install-core-prerelease-dependencies.sh
index cd157f53cf06..5efa3ddfe3bf 100755
--- a/ci/env/install-core-prerelease-dependencies.sh
+++ b/ci/env/install-core-prerelease-dependencies.sh
@@ -3,7 +3,7 @@
 set -e
 
 # install all unbounded dependencies in setup.py for ray core
-for dependency in attrs jsonschema aiosignal frozenlist requests grpcio
+for dependency in attrs jsonschema aiosignal frozenlist requests grpcio protobuf
 do
     python -m pip install -U --pre --upgrade-strategy=eager $dependency
 done
diff --git a/python/requirements.txt b/python/requirements.txt
index f18434fd3757..f60e47fed379 100644
--- a/python/requirements.txt
+++ b/python/requirements.txt
@@ -20,7 +20,7 @@ numpy >= 1.16
 opencensus
 packaging; python_version >= '3.10'
 prometheus_client >= 0.7.1, < 0.14.0
-protobuf >= 3.15.3, != 3.19.5, < 4.0.0
+protobuf >= 3.15.3, != 3.19.5
 py-spy >= 0.2.0
 pydantic >= 1.8, < 1.10.0
 pyyaml
diff --git a/python/setup.py b/python/setup.py
index c3fa4fd04fa7..ce459735b64c 100644
--- a/python/setup.py
+++ b/python/setup.py
@@ -311,7 +311,7 @@ def get_packages(self):
         "numpy >= 1.16; python_version < '3.9'",
         "numpy >= 1.19.3; python_version >= '3.9'",
         "packaging; python_version >= '3.10'",
-        "protobuf >= 3.15.3, < 4.0.0",
+        "protobuf >= 3.15.3, != 3.19.5",
         "pyyaml",
         "aiosignal",
         "frozenlist",
diff --git a/release/requirements.txt b/release/requirements.txt
index d6d9d4d57d4d..dc78a9a43f31 100644
--- a/release/requirements.txt
+++ b/release/requirements.txt
@@ -11,7 +11,7 @@ toml
 python-dotenv
 expiringdict
 requests
-protobuf >= 3.15.3, != 3.19.5, < 4.0.0
+protobuf >= 3.15.3, != 3.19.5
 pytz
 retry
 git+https://github.com/ray-project/xgboost_ray.git#egg=xgboost_ray
diff --git a/release/requirements_buildkite.txt b/release/requirements_buildkite.txt
index 561b46c55d54..d3c1cc138362 100644
--- a/release/requirements_buildkite.txt
+++ b/release/requirements_buildkite.txt
@@ -2,7 +2,7 @@ anyscale
 click
 boto3
 jinja2
-protobuf >= 3.15.3, != 3.19.5, < 4.0.0
+protobuf >= 3.15.3, != 3.19.5
 pydantic < 1.10.0
 pyyaml
 requests