diff --git a/src/RIGID/fix_rigid_small.cpp b/src/RIGID/fix_rigid_small.cpp
index 13208d4c4c434f4be2602a1447650dced9dca3f2..e6083f64937e5077ffac90c88ebe5014b393629a 100644
--- a/src/RIGID/fix_rigid_small.cpp
+++ b/src/RIGID/fix_rigid_small.cpp
@@ -114,6 +114,7 @@ FixRigidSmall::FixRigidSmall(LAMMPS *lmp, int narg, char **arg) :
   if (strcmp(arg[3],"molecule") == 0) {
     if (atom->molecule_flag == 0)
       error->all(FLERR,"Fix rigid/small requires atom attribute molecule");
+    bodyid = atom->molecule;
 
   } else if (strcmp(arg[3],"custom") == 0) {
     if (narg < 5) error->all(FLERR,"Illegal fix rigid/small command");