diff --git a/fancy_gym/utils/make_env_helpers.py b/fancy_gym/utils/make_env_helpers.py
index 5221423..18ab6ed 100644
--- a/fancy_gym/utils/make_env_helpers.py
+++ b/fancy_gym/utils/make_env_helpers.py
@@ -141,7 +141,7 @@ def make_bb(
     Returns: DMP wrapped gym env
 
     """
-    _verify_time_limit(traj_gen_kwargs.get("duration", None), kwargs.get("time_limit", None))
+    _verify_time_limit(traj_gen_kwargs.get("duration"), kwargs.get("time_limit"))
 
     learn_sub_trajs = black_box_kwargs.get('learn_sub_trajectories')
     do_replanning = black_box_kwargs.get('replanning_schedule')
diff --git a/test/test_black_box.py b/test/test_black_box.py
new file mode 100644
index 0000000..974e3b3
--- /dev/null
+++ b/test/test_black_box.py
@@ -0,0 +1,104 @@
+from itertools import chain
+from typing import Tuple, Type, Union, Optional
+
+import gym
+import numpy as np
+import pytest
+from gym import register
+from gym.wrappers import TimeLimit
+
+from fancy_gym.black_box.raw_interface_wrapper import RawInterfaceWrapper
+from gym.core import ActType, ObsType
+
+import fancy_gym
+
+SEED = 1
+ENV_IDS = ['Reacher5d-v0', 'dmc:ball_in_cup-catch', 'metaworld:reach-v2', 'Reacher-v2']
+WRAPPERS = [fancy_gym.envs.mujoco.reacher.MPWrapper, fancy_gym.dmc.suite.ball_in_cup.MPWrapper,
+            fancy_gym.meta.goal_object_change_mp_wrapper.MPWrapper, fancy_gym.open_ai.mujoco.reacher_v2.MPWrapper]
+ALL_MP_ENVS = chain(*fancy_gym.ALL_MOVEMENT_PRIMITIVE_ENVIRONMENTS.values())
+
+
+class ToyEnv(gym.Env):
+    observation_space = gym.spaces.Box(low=-1, high=1, shape=(1,), dtype=np.float64)
+    action_space = gym.spaces.Box(low=-1, high=1, shape=(1,), dtype=np.float64)
+    dt = 0.01
+
+    def reset(self, *, seed: Optional[int] = None, return_info: bool = False,
+              options: Optional[dict] = None) -> Union[ObsType, Tuple[ObsType, dict]]:
+        return np.array([-1])
+
+    def step(self, action: ActType) -> Tuple[ObsType, float, bool, dict]:
+        return np.array([-1]), 1, False, {}
+
+    def render(self, mode="human"):
+        pass
+
+
+class ToyWrapper(RawInterfaceWrapper):
+
+    @property
+    def current_pos(self) -> Union[float, int, np.ndarray, Tuple]:
+        return np.ones(self.action_space.shape)
+
+    @property
+    def current_vel(self) -> Union[float, int, np.ndarray, Tuple]:
+        return np.ones(self.action_space.shape)
+
+
+@pytest.fixture(scope="session", autouse=True)
+def setup():
+    register(
+        id=f'toy-v0',
+        entry_point='test.test_black_box:ToyEnv',
+        max_episode_steps=50,
+    )
+
+
+@pytest.mark.parametrize('env_id', ENV_IDS)
+def test_missing_wrapper(env_id: str):
+    with pytest.raises(ValueError):
+        fancy_gym.make_bb(env_id, [], {}, {}, {}, {}, {})
+
+
+@pytest.mark.parametrize('env_wrap', zip(ENV_IDS, WRAPPERS))
+def test_context_space(env_wrap: Tuple[str, Type[RawInterfaceWrapper]]):
+    env_id, wrapper_class = env_wrap
+    env = fancy_gym.make_bb(env_id, [wrapper_class], {},
+                            {'trajectory_generator_type': 'promp'},
+                            {'controller_type': 'motor'},
+                            {'phase_generator_type': 'linear'},
+                            {'basis_generator_type': 'rbf'})
+    # check if observation space matches with the specified mask values which are true
+    env_step = fancy_gym.make(env_id, SEED)
+    wrapper = wrapper_class(env_step)
+    assert env.observation_space.shape == wrapper.context_mask[wrapper.context_mask].shape
+
+
+@pytest.mark.parametrize('env_id', ENV_IDS)
+@pytest.mark.parametrize('reward_aggregation', [np.sum, np.mean, np.median, lambda x: np.mean(x[::2])])
+def test_aggregation(env_id: str, reward_aggregation: callable):
+    env = fancy_gym.make_bb('toy-v0', [ToyWrapper], {'reward_aggregation': reward_aggregation},
+                            {'trajectory_generator_type': 'promp'},
+                            {'controller_type': 'motor'},
+                            {'phase_generator_type': 'linear'},
+                            {'basis_generator_type': 'rbf'})
+    env.reset()
+
+    # ToyEnv only returns 1 as reward
+    assert env.step(env.action_space.sample())[1] == reward_aggregation(np.ones(50, ))
+
+
+@pytest.mark.parametrize('env_id', ENV_IDS)
+@pytest.mark.parametrize('add_time_aware_wrapper_before', [True, False])
+def test_learn_sub_trajectories(env_id: str, add_time_aware_wrapper_before: bool):
+    env_step = fancy_gym.make(env_id, SEED)
+    env = fancy_gym.make_bb(env_id, [], {}, {}, {}, {'phase_generator_type': 'linear'}, {})
+
+    # has time aware wrapper
+    if add_time_aware_wrapper_before:
+        pass
+
+    assert env.learn_sub_trajectories
+    assert env.learn_tau
+    assert env.observation_space == env_step.observation_space