diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 4c6abd36491365e0c1c96a8ee35a80db9ff58e28..4bd3a3c742abb1ef993f13f97affe87105b47245 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,5 +1,6 @@
 Unreleased changes
 ------------------
+* The fields ``.a`` is now read by default.
 
 Version 0
 ---------
diff --git a/km3io/offline.py b/km3io/offline.py
index d38578d60de688b9de16ec809bee81dcf92ca7ac..1ff221881f2d1077eaa1eea69e4626925c8f19f2 100644
--- a/km3io/offline.py
+++ b/km3io/offline.py
@@ -41,6 +41,7 @@ class OfflineReader(EventReader):
             "dir_y": "hits.dir.y",
             "dir_z": "hits.dir.z",
             "tot": "hits.tot",
+            "a": "mc_hits.a",  # hit amplitude (in p.e.)
             "trig": "hits.trig",  # non-zero if the hit is a triggered hit
         },
         "mc_hits": {