diff --git a/tianshou/highlevel/params/policy_wrapper.py b/tianshou/highlevel/params/policy_wrapper.py
index 09e5065..8bf43cc 100644
--- a/tianshou/highlevel/params/policy_wrapper.py
+++ b/tianshou/highlevel/params/policy_wrapper.py
@@ -54,7 +54,7 @@ class PolicyWrapperFactoryIntrinsicCuriosity(
     ) -> ICMPolicy:
         feature_net = self.feature_net_factory.create_module(envs, device)
         action_dim = envs.get_action_shape()
-        if type(action_dim) != int:
+        if not isinstance(action_dim, int):
             raise ValueError(f"Environment action shape must be an integer, got {action_dim}")
         feature_dim = feature_net.output_dim
         icm_net = IntrinsicCuriosityModule(