diff --git a/src/library.cpp b/src/library.cpp
index 2e2f7a3d0d..1a67624f21 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -673,7 +673,8 @@ void lammps_extract_box(void *handle, double *boxlo, double *boxhi,
 
 This function sets the simulation box dimensions (upper and lower bounds
 and tilt factors) from the provided data and then re-initializes the box
-information and all derived settings.
+information and all derived settings. It may only be called before atoms
+are created.
 
 \endverbatim
  *
@@ -692,12 +693,16 @@ void lammps_reset_box(void *handle, double *boxlo, double *boxhi,
 
   BEGIN_CAPTURE
   {
-    // error if box does not exist
-    if ((lmp->domain->box_exist == 0)
-        && (lmp->comm->me == 0)) {
-      lmp->error->warning(FLERR,"Calling lammps_reset_box without a box");
+    if (lmp->atom->natoms > 0)
+      lmp->error->all(FLERR,"Calling lammps_reset_box not supported when atoms exist");
+
+    // warn and do nothing if no box exists
+    if (lmp->domain->box_exist == 0) {
+      if (lmp->comm->me == 0)
+        lmp->error->warning(FLERR,"Ignoring call to lammps_reset_box without a box");
       return;
     }
+
     domain->boxlo[0] = boxlo[0];
     domain->boxlo[1] = boxlo[1];
     domain->boxlo[2] = boxlo[2];
diff --git a/unittest/c-library/test_library_properties.cpp b/unittest/c-library/test_library_properties.cpp
index 07e920bda7..cd405bfb93 100644
--- a/unittest/c-library/test_library_properties.cpp
+++ b/unittest/c-library/test_library_properties.cpp
@@ -161,6 +161,8 @@ TEST_F(LibraryProperties, box)
     boxhi[1] = 7.3;
     xy       = 0.1;
     if (!verbose) ::testing::internal::CaptureStdout();
+    // lammps_reset_box() may only be called without atoms
+    lammps_command(lmp, "delete_atoms group all bond yes");
     lammps_reset_box(lmp, boxlo, boxhi, xy, yz, xz);
     if (!verbose) ::testing::internal::GetCapturedStdout();
     lammps_extract_box(lmp, boxlo, boxhi, &xy, &yz, &xz, pflags, &boxflag);