diff --git a/sbi/inference/posteriors/ensemble_posterior.py b/sbi/inference/posteriors/ensemble_posterior.py
index b182559cb..1b251439f 100644
--- a/sbi/inference/posteriors/ensemble_posterior.py
+++ b/sbi/inference/posteriors/ensemble_posterior.py
@@ -137,7 +137,7 @@ def weights(self, weights: Optional[Union[List[float], Tensor]]) -> None:
             self._weights = torch.tensor([
                 1.0 / self.num_components for _ in range(self.num_components)
             ])
-        elif weights is Tensor or weights is List:
+        elif isinstance(weights, (Tensor, List)):
             self._weights = torch.tensor(weights) / sum(weights)
         else:
             raise TypeError