diff --git a/src/postprocessor/core/processor.py b/src/postprocessor/core/processor.py
index b010efd16c8fdbddea83a8a8cf7a8a560bafbd05..381729f82ce8b874f04d2afe5951a08ad8db5ead 100644
--- a/src/postprocessor/core/processor.py
+++ b/src/postprocessor/core/processor.py
@@ -193,6 +193,7 @@ class PostProcessor(ProcessABC):
         moset = set([tuple(x) for x in trap_mother])
         daset = set([tuple(x) for x in trap_daughter])
         picked_set = set([tuple(x) for x in indices])
+
         with h5py.File(self._filename, "a") as f:
             merge_events = f["modifiers/merges"][()]
         multii = pd.MultiIndex(
diff --git a/src/postprocessor/core/reshapers/picker.py b/src/postprocessor/core/reshapers/picker.py
index 1cc0bdc868c941f307d34ff9d17367e651101f3f..84e1c21f4ca5ea5566d512cd540e885e1ec4a41a 100644
--- a/src/postprocessor/core/reshapers/picker.py
+++ b/src/postprocessor/core/reshapers/picker.py
@@ -100,7 +100,7 @@ class Picker(LineageProcess):
             self._log(f"No lineage assignment")
             indices = np.array([])
 
-        return np.array(tuple(map(_str_to_int, x)) for x in indices)
+        return np.array([tuple(map(_str_to_int, x)) for x in indices])
 
     def switch_case(
         self,