diff --git a/Processes/Sibyll/sibyll_codes.dat b/Processes/Sibyll/sibyll_codes.dat
index fc8515886b07c5f5a8f7a9307a7f06b88a65366c..deacb8dc62a1987da785c3a7a1f0d85569c19fe2 100644
--- a/Processes/Sibyll/sibyll_codes.dat
+++ b/Processes/Sibyll/sibyll_codes.dat
@@ -16,6 +16,7 @@ Gamma 1 0 0
 Pi0 6 1 2
 # rho0 could interact but sibyll has no cross section/interaction length. was used for gamma had int
 Rho0 27 0 0
+y
 K0Long 11 1 3
 PiPlus 7 1 2
 PiMinus 8 1 2