diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 822e0cb..cb90552 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -31,18 +31,21 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
+          # Use uv for faster downloads
+          pip install uv
           # cpu version of pytorch
-          pip install torch==2.3.1 --index-url https://download.pytorch.org/whl/cpu
+          # See https://github.com/astral-sh/uv/issues/1497
+          uv pip install --system torch==2.3.1+cpu --index https://download.pytorch.org/whl/cpu
 
           # Install Atari Roms
-          pip install autorom
+          uv pip install --system autorom
           wget https://gist.githubusercontent.com/jjshoots/61b22aefce4456920ba99f2c36906eda/raw/00046ac3403768bfe45857610a3d333b8e35e026/Roms.tar.gz.b64
           base64 Roms.tar.gz.b64 --decode &> Roms.tar.gz
           AutoROM --accept-license --source-file Roms.tar.gz
 
-          pip install .[extra_no_roms,tests,docs]
+          uv pip install --system .[extra_no_roms,tests,docs]
           # Use headless version
-          pip install opencv-python-headless
+          uv pip install --system opencv-python-headless
       - name: Lint with ruff
         run: |
           make lint
diff --git a/docs/guide/sb3_contrib.rst b/docs/guide/sb3_contrib.rst
index 445832c..8ec912e 100644
--- a/docs/guide/sb3_contrib.rst
+++ b/docs/guide/sb3_contrib.rst
@@ -42,6 +42,7 @@ See documentation for the full list of included features.
 - `PPO with recurrent policy (RecurrentPPO aka PPO LSTM) <https://ppo-details.cleanrl.dev//2021/11/05/ppo-implementation-details/>`_
 - `Truncated Quantile Critics (TQC)`_
 - `Trust Region Policy Optimization (TRPO) <https://arxiv.org/abs/1502.05477>`_
+- `Batch Normalization in Deep Reinforcement Learning (CrossQ) <https://openreview.net/forum?id=PczQtTsTIX>`_
 
 
 **Gym Wrappers**:
diff --git a/docs/misc/changelog.rst b/docs/misc/changelog.rst
index af83d23..2c0974a 100644
--- a/docs/misc/changelog.rst
+++ b/docs/misc/changelog.rst
@@ -6,6 +6,8 @@ Changelog
 Release 2.4.0a10 (WIP)
 --------------------------
 
+**New algorithm: CrossQ in SB3 Contrib**
+
 .. note::
 
   DQN (and QR-DQN) models saved with SB3 < 2.4.0 will show a warning about
@@ -43,6 +45,10 @@ Bug Fixes:
 
 `SB3-Contrib`_
 ^^^^^^^^^^^^^^
+- Added ``CrossQ`` algorithm, from "Batch Normalization in Deep Reinforcement Learning" paper (@danielpalen)
+- Added ``BatchRenorm`` PyTorch layer used in ``CrossQ`` (@danielpalen)
+- Updated QR-DQN optimizer input to only include quantile_net parameters (@corentinlger)
+- Fixed loading QRDQN changes `target_update_interval` (@jak3122)
 
 `RL Zoo`_
 ^^^^^^^^^
@@ -61,6 +67,7 @@ Others:
 - Remove unnecessary SDE noise resampling in PPO update (@brn-dev)
 - Updated PyTorch version on CI to 2.3.1
 - Added a warning to recommend using CPU with on policy algorithms (A2C/PPO) and ``MlpPolicy``
+- Switched to uv to download packages faster on GitHub CI
 
 Bug Fixes:
 ^^^^^^^^^^
diff --git a/stable_baselines3/common/utils.py b/stable_baselines3/common/utils.py
index bcde1cf..4e9fbc2 100644
--- a/stable_baselines3/common/utils.py
+++ b/stable_baselines3/common/utils.py
@@ -46,7 +46,7 @@ def set_random_seed(seed: int, using_cuda: bool = False) -> None:
 
 
 # From stable baselines
-def explained_variance(y_pred: np.ndarray, y_true: np.ndarray) -> np.ndarray:
+def explained_variance(y_pred: np.ndarray, y_true: np.ndarray) -> float:
     """
     Computes fraction of variance that ypred explains about y.
     Returns 1 - Var[y-ypred] / Var[y]
@@ -62,7 +62,7 @@ def explained_variance(y_pred: np.ndarray, y_true: np.ndarray) -> np.ndarray:
     """
     assert y_true.ndim == 1 and y_pred.ndim == 1
     var_y = np.var(y_true)
-    return np.nan if var_y == 0 else 1 - np.var(y_true - y_pred) / var_y
+    return np.nan if var_y == 0 else float(1 - np.var(y_true - y_pred) / var_y)
 
 
 def update_learning_rate(optimizer: th.optim.Optimizer, learning_rate: float) -> None:
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 4cc8b7e..81f1341 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -177,7 +177,7 @@ def test_custom_vec_env(tmp_path):
 
 
 @pytest.mark.parametrize("direct_policy", [False, True])
-def test_evaluate_policy(direct_policy: bool):
+def test_evaluate_policy(direct_policy):
     model = A2C("MlpPolicy", "Pendulum-v1", seed=0)
     n_steps_per_episode, n_eval_episodes = 200, 2