diff --git a/km3buu/output.py b/km3buu/output.py
index 4ae54f75d782fb45d99e6b763ba1bd83362b12ad..87fe0c6c6cc226b09fd42f3628ce0bc07cb72af0 100644
--- a/km3buu/output.py
+++ b/km3buu/output.py
@@ -260,7 +260,7 @@ class GiBUUOutput:
     def mean_xsec(self):
         if self.flux_data is None:
             return lambda energy: self.xsection["sum"]
-        else
+        else:
             root_tupledata = self.arrays
             energies = np.array(root_tupledata.lepIn_E)
             weights = self._event_xsec(root_tupledata)