diff --git a/qgym/envs/routing/routing_state.py b/qgym/envs/routing/routing_state.py
index 20f2685..6133e97 100644
--- a/qgym/envs/routing/routing_state.py
+++ b/qgym/envs/routing/routing_state.py
@@ -291,7 +291,7 @@ def obtain_observation(
             is_legal_surpass = np.fromiter(
                 iter=starmap(self.is_legal_surpass, interaction_gates_ahead),
                 count=len(interaction_gates_ahead),
-                dtype=np.int8,
+                dtype=np.int_,
             )
             observation["is_legal_surpass"] = is_legal_surpass