diff --git a/src/deprecated.cpp b/src/deprecated.cpp
index 3558935cb3..81a05307cb 100644
--- a/src/deprecated.cpp
+++ b/src/deprecated.cpp
@@ -32,6 +32,10 @@ void Deprecated::command(int narg, char **arg)
   if (cmd == "DEPRECATED") {
     if (lmp->comm->me == 0) utils::logmesg(lmp, "\nCommand 'DEPRECATED' is a dummy command\n\n");
     return;
+  } else if (cmd == "box") {
+    if (lmp->comm->me == 0)
+      utils::logmesg(lmp, "\nThe 'box' command has been removed and will be ignored\n\n");
+    return;
   } else if (cmd == "reset_ids") {
     if (lmp->comm->me == 0)
       utils::logmesg(lmp, "\n'reset_ids' has been renamed to 'reset_atom_ids'\n\n");
diff --git a/src/deprecated.h b/src/deprecated.h
index e2e7e396e9..2eb334b3ef 100644
--- a/src/deprecated.h
+++ b/src/deprecated.h
@@ -14,6 +14,7 @@
 #ifdef COMMAND_CLASS
 // clang-format off
 CommandStyle(DEPRECATED,Deprecated);
+CommandStyle(box,Deprecated);
 CommandStyle(reset_ids,Deprecated);
 CommandStyle(kim_init,Deprecated);
 CommandStyle(kim_interactions,Deprecated);
diff --git a/src/domain.cpp b/src/domain.cpp
index 6ed91d0ea8..c51f222483 100644
--- a/src/domain.cpp
+++ b/src/domain.cpp
@@ -82,7 +82,6 @@ Domain::Domain(LAMMPS *lmp) : Pointers(lmp)
   minzlo = minzhi = 0.0;
 
   triclinic = 0;
-  tiltsmall = 1;
 
   boxlo[0] = boxlo[1] = boxlo[2] = -0.5;
   boxhi[0] = boxhi[1] = boxhi[2] = 0.5;
@@ -218,10 +217,8 @@ void Domain::set_initial_box(int expandflag)
     if ((fabs(xy/(boxhi[0]-boxlo[0])) > 0.5 && xperiodic) ||
         (fabs(xz/(boxhi[0]-boxlo[0])) > 0.5 && xperiodic) ||
         (fabs(yz/(boxhi[1]-boxlo[1])) > 0.5 && yperiodic)) {
-      if (tiltsmall)
-        error->all(FLERR,"Triclinic box skew is too large");
-      else if (comm->me == 0)
-        error->warning(FLERR,"Triclinic box skew is large");
+      if (comm->me == 0)
+        error->warning(FLERR,"Triclinic box skew is large. LAMMPS will run inefficiently.");
     }
   }
 
@@ -1874,26 +1871,6 @@ void Domain::set_boundary(int narg, char **arg, int flag)
   }
 }
 
-/* ----------------------------------------------------------------------
-   set domain attributes
-------------------------------------------------------------------------- */
-
-void Domain::set_box(int narg, char **arg)
-{
-  if (narg < 1) utils::missing_cmd_args(FLERR, "box", error);
-
-  int iarg = 0;
-  while (iarg < narg) {
-    if (strcmp(arg[iarg],"tilt") == 0) {
-      if (iarg+2 > narg) utils::missing_cmd_args(FLERR, "box tilt", error);
-      if (strcmp(arg[iarg+1],"small") == 0) tiltsmall = 1;
-      else if (strcmp(arg[iarg+1],"large") == 0) tiltsmall = 0;
-      else error->all(FLERR,"Unknown box tilt argument: {}", arg[iarg+1]);
-      iarg += 2;
-    } else error->all(FLERR,"Unknown box keyword: {}", arg[iarg]);
-  }
-}
-
 /* ----------------------------------------------------------------------
    print box info, orthogonal or triclinic
 ------------------------------------------------------------------------- */
diff --git a/src/domain.h b/src/domain.h
index 8830c5d051..7d3194ccc9 100644
--- a/src/domain.h
+++ b/src/domain.h
@@ -41,7 +41,6 @@ class Domain : protected Pointers {
                          // 3 = shrink-wrap non-per w/ min
 
   int triclinic;    // 0 = orthog box, 1 = triclinic
-  int tiltsmall;    // 1 if limit tilt, else 0
 
   // orthogonal box
 
@@ -141,7 +140,6 @@ class Domain : protected Pointers {
   const std::vector<Region *> get_region_by_style(const std::string &) const;
   const std::vector<Region *> get_region_list();
   void set_boundary(int, char **, int);
-  void set_box(int, char **);
   void print_box(const std::string &);
   void boundary_string(char *);
 
diff --git a/src/input.cpp b/src/input.cpp
index 5128f0261f..a3c363b639 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -772,7 +772,6 @@ int Input::execute_command()
   else if (!strcmp(command,"bond_style")) bond_style();
   else if (!strcmp(command,"bond_write")) bond_write();
   else if (!strcmp(command,"boundary")) boundary();
-  else if (!strcmp(command,"box")) box();
   else if (!strcmp(command,"comm_modify")) comm_modify();
   else if (!strcmp(command,"comm_style")) comm_style();
   else if (!strcmp(command,"compute")) compute();
@@ -1411,15 +1410,6 @@ void Input::boundary()
 
 /* ---------------------------------------------------------------------- */
 
-void Input::box()
-{
-  if (domain->box_exist)
-    error->all(FLERR,"Box command after simulation box is defined");
-  domain->set_box(narg,arg);
-}
-
-/* ---------------------------------------------------------------------- */
-
 void Input::comm_modify()
 {
   comm->modify_params(narg,arg);
diff --git a/src/input.h b/src/input.h
index de4c393693..ebd7c13331 100644
--- a/src/input.h
+++ b/src/input.h
@@ -94,7 +94,6 @@ class Input : protected Pointers {
   void bond_style();
   void bond_write();
   void boundary();
-  void box();
   void comm_modify();
   void comm_style();
   void compute();