diff --git a/.rootlogon.C b/.rootlogon.C
index 5ce6226828996f7cf8493ce4b736d6ff82c6a826..b63b6b0553a11a689970209b576f728d0c235b90 100644
--- a/.rootlogon.C
+++ b/.rootlogon.C
@@ -3,6 +3,7 @@
   gROOT->ProcessLine(".include include");
 
   R__LOAD_LIBRARY(fmt)
+  R__LOAD_LIBRARY(HepMC3)
 
   // Setting for Graphs
   gROOT->SetStyle("Plain");