diff --git a/src/fix_box_relax.cpp b/src/fix_box_relax.cpp
index 2e4c304917..1660b20b1f 100644
--- a/src/fix_box_relax.cpp
+++ b/src/fix_box_relax.cpp
@@ -260,7 +260,7 @@ FixBoxRelax::FixBoxRelax(LAMMPS *lmp, int narg, char **arg) :
                "Cannot use fix box/relax on a 2nd non-periodic dimension");
   if (p_flag[5] && domain->yperiodic == 0)
     error->all(FLERR,
-               "Cannot use fix box/relax on a 2nd non-periodic dimensio");
+               "Cannot use fix box/relax on a 2nd non-periodic dimension");
 
   if (scaleyz == 1 && domain->zperiodic == 0)
     error->all(FLERR,"Cannot use fix box/relax "
diff --git a/src/fix_box_relax.h b/src/fix_box_relax.h
index ecf795c593..fb5e00b65a 100644
--- a/src/fix_box_relax.h
+++ b/src/fix_box_relax.h
@@ -125,6 +125,18 @@ When specifying an off-diagonal pressure component, the 2nd of the two
 dimensions must be periodic.  E.g. if the xy component is specified,
 then the y dimension must be periodic.
 
+E: Cannot use fix box/relax with tilt factor scaling on a 2nd non-periodic dimension"
+
+When specifying scaling on a tilt factor component, the 2nd of the two
+dimensions must be periodic.  E.g. if the xy component is specified,
+then the y dimension must be periodic.
+
+E: Cannot use fix box/relax with both relaxation and scaling on a tilt factor
+
+When specifying scaling on a tilt factor component, that component can not
+also be controlled by the barostat. E.g. if scalexy yes is specified and
+also keyword tri or xy, this is wrong.
+
 E: Can not specify Pxy/Pxz/Pyz in fix box/relax with non-triclinic box
 
 Only triclinic boxes can be used with off-diagonal pressure components.