diff --git a/km3buu/output.py b/km3buu/output.py
index 2cd5ba605dca33060b760e22edcd68dde480040c..1578b240bf742adebae588f1864eec3a7211f281 100644
--- a/km3buu/output.py
+++ b/km3buu/output.py
@@ -220,7 +220,6 @@ class GiBUUOutput:
                 ) + 1
                 tmp_df.index = tmp_df.index.set_levels(new_indices, level=0)
                 df = df.append(tmp_df)
-        df.columns = [col[0] for col in df.columns]
         sec_df = df[df.index.get_level_values(1) == 0]
         sec_df.loc[:, "E"] = sec_df.lepOut_E
         sec_df.loc[:, "Px"] = sec_df.lepOut_Px
diff --git a/requirements.txt b/requirements.txt
index 5da2c627b78219748c05846bc42611628f3d9c1f..cf7e0dfef53e7731aeac46400a6c907ce2ec0658 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -7,6 +7,6 @@ particle
 click
 f90nml
 uproot4
-awkward1
+awkward1>=0.4.4
 pandas
 mendeleev