diff --git a/nifty6/minimization/metric_gaussian_kl.py b/nifty6/minimization/metric_gaussian_kl.py
index a4f1589e416b7c0a5d3123a9a6d0f210da53424c..606f333d00fb9e9d1f04ab9dde9be9762ce90762 100644
--- a/nifty6/minimization/metric_gaussian_kl.py
+++ b/nifty6/minimization/metric_gaussian_kl.py
@@ -246,7 +246,7 @@ class MetricGaussianKL(Energy):
     def samples(self):
         if self._comm is not None:
             res = self._comm.allgather(self._samples)
-            res = [item for sublist in res for item in sublist]
+            res = tuple(item for sublist in res for item in sublist)
         else:
             res = self._samples
         if self._mirror_samples: