diff --git a/src/atom.cpp b/src/atom.cpp
index a206408c43..6faffd105c 100644
--- a/src/atom.cpp
+++ b/src/atom.cpp
@@ -2128,7 +2128,7 @@ void Atom::add_molecule(int narg, char **arg)
   if (narg < 1) utils::missing_cmd_args(FLERR, "molecule", error);
 
   if (find_molecule(arg[0]) >= 0)
-    error->all(FLERR,(int) 0, "Reuse of molecule template ID {}", arg[0]);
+    error->all(FLERR, Error::ARGZERO, "Reuse of molecule template ID {}", arg[0]);
 
   // 1st molecule in set stores nset = # of mols, others store nset = 0
   // ifile = count of molecules in set
diff --git a/src/error.cpp b/src/error.cpp
index 946cc19fd6..f8c1eaefd8 100644
--- a/src/error.cpp
+++ b/src/error.cpp
@@ -130,6 +130,7 @@ void Error::all(const std::string &file, int line, int failed, const std::string
   // add text about the input following the error message
 
   if (failed > NOLASTLINE) mesg += utils::point_to_error(input, failed);
+  if (failed == ARGZERO) mesg += utils::point_to_error(input, 0);
   if (me == 0) utils::logmesg(lmp,mesg);
   utils::flush_buffers(lmp);
 
@@ -162,6 +163,7 @@ void Error::one(const std::string &file, int line, int failed, const std::string
 
   std::string mesg = fmt::format("ERROR on proc {}: {} ({}:{})\n", me, str, truncpath(file), line);
   if (failed > NOPOINTER) mesg += utils::point_to_error(input, failed);
+  if (failed > ARGZERO) mesg += utils::point_to_error(input, 0);
   utils::logmesg(lmp,mesg);
 
   if (universe->nworlds > 1)
diff --git a/src/error.h b/src/error.h
index 0c446667e0..ba1bd655d0 100644
--- a/src/error.h
+++ b/src/error.h
@@ -29,6 +29,7 @@ class Error : protected Pointers {
 
   static constexpr int NOPOINTER = -2;
   static constexpr int NOLASTLINE = -3;
+  static constexpr int ARGZERO = -99;
 
   // regular error calls
 
diff --git a/src/molecule.cpp b/src/molecule.cpp
index 2b8c347a9d..20bb72ef07 100644
--- a/src/molecule.cpp
+++ b/src/molecule.cpp
@@ -58,7 +58,7 @@ Molecule::Molecule(LAMMPS *lmp, int narg, char **arg, int &index) :
 
   id = utils::strdup(arg[0]);
   if (!utils::is_id(id))
-    error->all(FLERR, (int) 0,
+    error->all(FLERR, Error::ARGZEO,
                "Molecule template ID {} must have only alphanumeric or underscore"
                " characters",
                id);