diff --git a/setup.py b/setup.py
index 115541a753f..6ad31563f28 100644
--- a/setup.py
+++ b/setup.py
@@ -58,7 +58,7 @@
 from setuptools import find_packages, setup
 
 
-__version__ = "0.9.4"  # expected format is one of x.y.z.dev0, or x.y.z.rc1 or x.y.z (no to dashes, yes to dots)
+__version__ = "0.9.5.dev0"  # expected format is one of x.y.z.dev0, or x.y.z.rc1 or x.y.z (no to dashes, yes to dots)
 
 REQUIRED_PKGS = [
     "torch>=1.4.0",
diff --git a/trl/__init__.py b/trl/__init__.py
index 4b8e0f6b88a..0879b8311e0 100644
--- a/trl/__init__.py
+++ b/trl/__init__.py
@@ -1,6 +1,6 @@
 # flake8: noqa
 
-__version__ = "0.9.4"
+__version__ = "0.9.5.dev0"
 
 from typing import TYPE_CHECKING
 from .import_utils import _LazyModule, is_diffusers_available, OptionalDependencyNotAvailable