diff --git a/km3io/definitions.py b/km3io/definitions.py
index d585e84b65072ee065b5105db6090fea48262e6a..b749dba26d23b69036b35bfea03a64a238856c29 100644
--- a/km3io/definitions.py
+++ b/km3io/definitions.py
@@ -36,4 +36,4 @@ reconstruction_idx = {v: k for k, v in reconstruction.items()}
 w2list_genhen_idx = {v: k for k, v in w2list_genhen.items()}
 w2list_gseagen_idx = {v: k for k, v in w2list_gseagen.items()}
 pmt_status_idx = {v: k for k, v in pmt_status.items()}
-trkmembers_idx = {v: k for k, v in trksmembers.items()}
+trkmembers_idx = {v: k for k, v in trkmembers.items()}