diff --git a/README.md b/README.md
index 95949b2..0a72370 100644
--- a/README.md
+++ b/README.md
@@ -77,6 +77,9 @@ pip install jeb-utils --index-url https://repo.jcloud-services.ddns.net/simple/
 - `create_file_if_not_exists`: Creates a file if it does not exist.
 
 ## Changelog
+### Version 0.3.1
+- Fatal bug fix: `typing.Union` in `jeb_utils.utils` was used but not imported
+
 ### Version 0.3.0
 - Make library backward compatible: use `typing.Union` instead of the `|` operator
 
diff --git a/pyproject.toml b/pyproject.toml
index 6c88000..1b7d9e4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "jeb-utils"
-version = "0.3.0"
+version = "0.3.1"
 description = "Common utils for JEB client and server."
 dependencies = ["cryptography"]
 license = "Apache-2.0"
\ No newline at end of file
diff --git a/src/jeb_utils/utils.py b/src/jeb_utils/utils.py
index c5a519d..5b6d0e7 100644
--- a/src/jeb_utils/utils.py
+++ b/src/jeb_utils/utils.py
@@ -13,7 +13,7 @@
 #  limitations under the License.
 
 import os
-from typing import Tuple, Literal, Sequence
+from typing import Tuple, Literal, Sequence, Union
 import ipaddress
 
 __all__ = [