diff --git a/km3io/gseagen.py b/km3io/gseagen.py
index c89d43d507991ce6027c72661c04a4d02f40db0e..4ce784cfb67e94202cf0fe8748d1f1f3d56465c5 100644
--- a/km3io/gseagen.py
+++ b/km3io/gseagen.py
@@ -42,12 +42,4 @@ class GSGReader:
 
     @cached_property
     def events(self):
-        gseagen_events_mapper = BranchMapper(name="Events",
-                                             key="Events",
-                                             extra={},
-                                             exclude={},
-                                             update={},
-                                             attrparser=lambda x: x,
-                                             flat=True,
-                                             interpretations={})
-        return Branch(self._fobj, gseagen_events_mapper)
+        return Branch(self._fobj, BranchMapper(name="Events", key="Events"))
diff --git a/km3io/offline.py b/km3io/offline.py
index 3949d0dc40ebdfa0f567ed9597352806941123e3..73cb13c3bf9484180d03ecd27b4e42d60d143337 100644
--- a/km3io/offline.py
+++ b/km3io/offline.py
@@ -29,10 +29,7 @@ EVENTS_MAP = BranchMapper(name="events",
                               'n_mc_hits': 'mc_hits',
                               'n_tracks': 'trks',
                               'n_mc_tracks': 'mc_trks'
-                          },
-                          attrparser=lambda a: a,
-                          flat=True,
-                          interpretations={})
+                          })
 
 SUBBRANCH_MAPS = [
     BranchMapper(name="tracks",
@@ -40,44 +37,33 @@ SUBBRANCH_MAPS = [
                  extra={},
                  exclude=EXCLUDE_KEYS +
                  ['trks.usr_data', 'trks.usr', 'trks.fUniqueID', 'trks.fBits'],
-                 update={},
                  attrparser=_nested_mapper,
-                 flat=False,
-                 interpretations={}),
+                 flat=False),
     BranchMapper(name="mc_tracks",
                  key="mc_trks",
-                 extra={},
                  exclude=EXCLUDE_KEYS + [
                      'mc_trks.usr_data', 'mc_trks.usr', 'mc_trks.rec_stages',
                      'mc_trks.fitinf', 'mc_trks.fUniqueID', 'mc_trks.fBits'
                  ],
-                 update={},
                  attrparser=_nested_mapper,
-                 flat=False,
-                 interpretations={}),
+                 flat=False),
     BranchMapper(name="hits",
                  key="hits",
-                 extra={},
                  exclude=EXCLUDE_KEYS + [
                      'hits.usr', 'hits.pmt_id', 'hits.origin', 'hits.a',
                      'hits.pure_a', 'hits.fUniqueID', 'hits.fBits'
                  ],
-                 update={},
                  attrparser=_nested_mapper,
-                 flat=False,
-                 interpretations={}),
+                 flat=False),
     BranchMapper(name="mc_hits",
                  key="mc_hits",
-                 extra={},
                  exclude=EXCLUDE_KEYS + [
                      'mc_hits.usr', 'mc_hits.dom_id', 'mc_hits.channel_id',
                      'mc_hits.tdc', 'mc_hits.tot', 'mc_hits.trig',
                      'mc_hits.fUniqueID', 'mc_hits.fBits'
                  ],
-                 update={},
                  attrparser=_nested_mapper,
-                 flat=False,
-                 interpretations={}),
+                 flat=False),
 ]