diff --git a/flatland/envs/schedule_generators.py b/flatland/envs/schedule_generators.py
index 5883794f4e0b2675c92becc516e57c85f47e060b..9fc74368525fe775f97b5cb830c2d6bb7de9a771 100644
--- a/flatland/envs/schedule_generators.py
+++ b/flatland/envs/schedule_generators.py
@@ -199,12 +199,12 @@ def random_schedule_generator(speed_ratio_map: Optional[Mapping[float, float]] =
                     valid_positions.append((r, c))
         if len(valid_positions) == 0:
             return Schedule(agent_positions=[], agent_directions=[],
-                            agent_targets=[], agent_speeds=[])
+                            agent_targets=[], agent_speeds=[], agent_malfunction_rates=None)
 
         if len(valid_positions) < num_agents:
             warnings.warn("schedule_generators: len(valid_positions) < num_agents")
             return Schedule(agent_positions=[], agent_directions=[],
-                            agent_targets=[], agent_speeds=[])
+                            agent_targets=[], agent_speeds=[],  agent_malfunction_rates=None)
 
         agents_position_idx = [i for i in np.random.choice(len(valid_positions), num_agents, replace=False)]
         agents_position = [valid_positions[agents_position_idx[i]] for i in range(num_agents)]