diff --git a/pyproject.toml b/pyproject.toml
index 81bf889d..b4b7362b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -64,7 +64,7 @@ homepage = "https://eclecticsheep.ai"
 repository = "https://github.com/Eclectic-Sheep/sheeprl"
 
 [project.optional-dependencies]
-test = ["pytest==7.3.1", "pytest-timeout==2.1.0", "pytest-coverage"]
+test = ["pytest==7.3.1", "pytest-timeout==2.1.0", "pytest-coverage", "importlib_resources>=6.2.0"]
 dev = [
   "pre-commit==3.5.0",
   "mypy==1.2.0",
diff --git a/sheeprl/__init__.py b/sheeprl/__init__.py
index 46d30d43..5ec12dc8 100644
--- a/sheeprl/__init__.py
+++ b/sheeprl/__init__.py
@@ -52,7 +52,7 @@
 np.int = np.int64
 np.bool = bool
 
-__version__ = "0.5.4"
+__version__ = "0.5.5.dev0"
 
 
 # Replace `moviepy.decorators.use_clip_fps_by_default` method to work with python 3.8, 3.9, and 3.10
diff --git a/sheeprl/algos/a2c/agent.py b/sheeprl/algos/a2c/agent.py
index 100b7d41..c1ad2913 100644
--- a/sheeprl/algos/a2c/agent.py
+++ b/sheeprl/algos/a2c/agent.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 from typing import Any, Dict, List, Optional, Sequence, Tuple
 
 import gymnasium
diff --git a/sheeprl/algos/sac_ae/agent.py b/sheeprl/algos/sac_ae/agent.py
index 727e0cb3..5292bd73 100644
--- a/sheeprl/algos/sac_ae/agent.py
+++ b/sheeprl/algos/sac_ae/agent.py
@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import copy
 from math import prod
 from typing import Any, Dict, List, Optional, Sequence, SupportsFloat, Tuple, Union