diff --git a/src/lammps.cpp b/src/lammps.cpp
index ff6db7a667..3f44ebe25f 100644
--- a/src/lammps.cpp
+++ b/src/lammps.cpp
@@ -204,6 +204,7 @@ LAMMPS::LAMMPS(int narg, char **arg, MPI_Comm communicator)
         error->universe_all(FLERR,"Invalid command-line argument");
       delete [] suffix;
       delete [] suffix2;
+      suffix2 = NULL;
       suffix_enable = 1;
       // hybrid option to set fall-back for suffix2
       if (strcmp(arg[iarg+1],"hybrid") == 0) {