diff --git a/src/fix_rigid.cpp b/src/fix_rigid.cpp
index 633916748a..bbd29a6a1d 100644
--- a/src/fix_rigid.cpp
+++ b/src/fix_rigid.cpp
@@ -93,8 +93,8 @@ FixRigid::FixRigid(LAMMPS *lmp, int narg, char **arg) :
 
   } else if (strcmp(arg[3],"molecule") == 0) {
     iarg = 4;
-    if (atom->molecular == 0)
-      error->all("Must use a molecular atom style with fix rigid molecule");
+    if (atom->molecule_flag == 0)
+      error->all("Fix rigid molecule requires atom attribute molecule");
 
     int *mask = atom->mask;
     int *molecule = atom->molecule;
diff --git a/src/neighbor.cpp b/src/neighbor.cpp
index 4cd449659f..bc45df5592 100644
--- a/src/neighbor.cpp
+++ b/src/neighbor.cpp
@@ -1417,9 +1417,9 @@ void Neighbor::modify_params(int narg, char **arg)
 
       } else if (strcmp(arg[iarg+1],"molecule") == 0) {
 	if (iarg+3 > narg) error->all("Illegal neigh_modify command");
-	if (atom->molecular == 0) {
+	if (atom->molecule_flag == 0) {
 	  char *str = (char *)
-	    "Must use molecular atom style with neigh_modify exclude molecule";
+	    "Neigh_modify exclude molecule requires atom attribute molecule";
 	  error->all(str);
 	}
 	if (nex_mol == maxex_mol) {