diff --git a/stable_baselines3/common/off_policy_algorithm.py b/stable_baselines3/common/off_policy_algorithm.py
index 35af80c..36ad34b 100644
--- a/stable_baselines3/common/off_policy_algorithm.py
+++ b/stable_baselines3/common/off_policy_algorithm.py
@@ -2,7 +2,7 @@ import io
 import pathlib
 import time
 import warnings
-from typing import Any, Callable, Dict, List, Mapping, Optional, Tuple, Type, Union
+from typing import Any, Callable, Dict, List, Optional, Tuple, Type, Union
 
 import gym
 import numpy as np
@@ -76,8 +76,8 @@ class OffPolicyAlgorithm(BaseAlgorithm):
         env: Union[GymEnv, str],
         policy_base: Type[BasePolicy],
         learning_rate: Union[float, Callable],
-        replay_buffer_cls: Type[ReplayBuffer] = None,
-        replay_buffer_kwargs: Optional[Mapping[str, Any]] = None,
+        replay_buffer_class: Optional[Type[ReplayBuffer]] = None,
+        replay_buffer_kwargs: Optional[Dict[str, Any]] = None,
         buffer_size: int = int(1e6),
         learning_starts: int = 100,
         batch_size: int = 256,
@@ -148,13 +148,13 @@ class OffPolicyAlgorithm(BaseAlgorithm):
         self.use_sde_at_warmup = use_sde_at_warmup
 
         self.replay_buffer = None
-        self.replay_buffer_cls = replay_buffer_cls or ReplayBuffer
+        self.replay_buffer_class = replay_buffer_class or ReplayBuffer
         self.replay_buffer_kwargs = dict(replay_buffer_kwargs or {})
 
     def _setup_model(self) -> None:
         self._setup_lr_schedule()
         self.set_random_seed(self.seed)
-        self.replay_buffer = self.replay_buffer_cls(
+        self.replay_buffer = self.replay_buffer_class(
             self.buffer_size,
             self.observation_space,
             self.action_space,
diff --git a/stable_baselines3/dqn/dqn.py b/stable_baselines3/dqn/dqn.py
index ed0f655..b030b43 100644
--- a/stable_baselines3/dqn/dqn.py
+++ b/stable_baselines3/dqn/dqn.py
@@ -70,6 +70,8 @@ class DQN(OffPolicyAlgorithm):
         gradient_steps: int = 1,
         n_episodes_rollout: int = -1,
         optimize_memory_usage: bool = False,
+        replay_buffer_class: Optional[Type[ReplayBuffer]] = None,
+        replay_buffer_kwargs: Optional[Dict[str, Any]] = None,
         target_update_interval: int = 10000,
         exploration_fraction: float = 0.1,
         exploration_initial_eps: float = 1.0,
@@ -89,8 +91,8 @@ class DQN(OffPolicyAlgorithm):
             env,
             DQNPolicy,
             learning_rate,
-            ReplayBuffer,
-            None,
+            replay_buffer_class,
+            replay_buffer_kwargs,
             buffer_size,
             learning_starts,
             batch_size,
diff --git a/stable_baselines3/sac/sac.py b/stable_baselines3/sac/sac.py
index 396087b..f631ec6 100644
--- a/stable_baselines3/sac/sac.py
+++ b/stable_baselines3/sac/sac.py
@@ -86,6 +86,8 @@ class SAC(OffPolicyAlgorithm):
         n_episodes_rollout: int = -1,
         action_noise: Optional[ActionNoise] = None,
         optimize_memory_usage: bool = False,
+        replay_buffer_class: Optional[Type[ReplayBuffer]] = None,
+        replay_buffer_kwargs: Optional[Dict[str, Any]] = None,
         ent_coef: Union[str, float] = "auto",
         target_update_interval: int = 1,
         target_entropy: Union[str, float] = "auto",
@@ -106,8 +108,8 @@ class SAC(OffPolicyAlgorithm):
             env,
             SACPolicy,
             learning_rate,
-            ReplayBuffer,
-            None,
+            replay_buffer_class,
+            replay_buffer_kwargs,
             buffer_size,
             learning_starts,
             batch_size,