diff --git a/Processes/Sibyll/sibyll_codes.dat b/Processes/Sibyll/sibyll_codes.dat
index 08209d0f9f27249932c850199dc7cb5c12c92ef9..45aa507f964304a941b2ccf5c257f52e11f46c26 100644
--- a/Processes/Sibyll/sibyll_codes.dat
+++ b/Processes/Sibyll/sibyll_codes.dat
@@ -17,6 +17,8 @@ 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
 K0Long 11 1 3
+K0 21 0 3
+K0Bar 22 0 3
 PiPlus 7 1 2
 PiMinus 8 1 2
 RhoPlus 25 0 0