diff --git a/overcooked_simulator/simulation_runner.py b/overcooked_simulator/simulation_runner.py
index 846a56bcbb2e243c1df54ae287104c8eedacb90a..461724c1ece3c45bb3c0bcb4fed163a94030507f 100644
--- a/overcooked_simulator/simulation_runner.py
+++ b/overcooked_simulator/simulation_runner.py
@@ -23,7 +23,7 @@ class Simulator(Thread):
         self.step_frequency: int = frequency
         self.prefered_sleeptime_ns: float = 1e9 / self.step_frequency
 
-        self.env = env_class()
+        self.env: Environment = env_class()
 
         super().__init__()
 
diff --git a/tests/test_start.py b/tests/test_start.py
index 0cc343f7846358e7cffd35f6b4da72a5ba60e15f..b60b38a91c31467e69bf1f54a8193387a66be12b 100644
--- a/tests/test_start.py
+++ b/tests/test_start.py
@@ -3,6 +3,8 @@ from overcooked_simulator.player import Player
 from overcooked_simulator.overcooked_environment import Environment, Action
 import numpy as np
 import time
+from overcooked_simulator.counters import Counter
+
 
 def test_player_registration():
 
@@ -47,3 +49,25 @@ def test_simulator_frequency():
     lower = frequency * running_time_seconds * (1-accepted_tolerance)
     upper = frequency * running_time_seconds * (1+accepted_tolerance)
     assert sim.env.c > lower and sim.env.c < upper, "Timing error in the environment at 1000hz"
+
+
+def test_collision_detection():
+    sim = Simulator(Environment, 200)
+    counter_pos = np.array([0, 100])
+    counter = Counter(counter_pos)
+    sim.env.counters = [counter]
+    player1 = Player("p1", np.array([0, 0]))
+    player2 = Player("p2", np.array([0, 200]))
+    sim.register_player(player1)
+    sim.register_player(player2)  # same player name
+
+    sim.start()
+    assert not sim.env.detect_collision_counters(player1), "Should not collide"
+    assert not sim.env.detect_player_collision(player1), "Should not collide yet."
+
+    player1.move_abs(counter_pos)
+    assert sim.env.detect_collision_counters(player1), "Player and counter at same pos."
+    player2.move_abs(counter_pos)
+    assert sim.env.detect_player_collision(player1), "Players at same pos."
+
+    sim.stop()