diff --git a/hydradx/model/run.py b/hydradx/model/run.py
index fc0c1e9d..aa349795 100644
--- a/hydradx/model/run.py
+++ b/hydradx/model/run.py
@@ -23,7 +23,7 @@ def run(initial_state: GlobalState, time_steps: int, silent: bool = False) -> li
         new_global_state.evolve()
 
         # agent actions
-        agent_ids = deepcopy(new_global_state.agents.keys())
+        agent_ids = deepcopy(list(new_global_state.agents.keys()))
         for agent_id in agent_ids:
             agent = new_global_state.agents[agent_id]
             if agent.trade_strategy: