diff --git a/src/min.cpp b/src/min.cpp
index cce07e1b8b..6e568aee0b 100644
--- a/src/min.cpp
+++ b/src/min.cpp
@@ -241,12 +241,21 @@ void Min::setup()
 
   // remove these restriction eventually
 
-  if (nextra_global && searchflag == 0)
-    error->all(FLERR,
-               "Cannot use a damped dynamics min style with fix box/relax");
-  if (nextra_atom && searchflag == 0)
-    error->all(FLERR,
-               "Cannot use a damped dynamics min style with per-atom DOF");
+  if (searchflag == 0) {
+    if (nextra_global)
+      error->all(FLERR,
+                 "Cannot use a damped dynamics min style with fix box/relax");
+    if (nextra_atom)
+      error->all(FLERR,
+                 "Cannot use a damped dynamics min style with per-atom DOF");
+  }
+
+  if (strcmp(update->minimize_style,"hftn") == 0) {
+    if (nextra_global)
+      error->all(FLERR, "Cannot use hftn min style with fix box/relax");
+    if (nextra_atom)
+      error->all(FLERR, "Cannot use hftn min style with per-atom DOF");
+  }
 
   // atoms may have migrated in comm->exchange()
 
diff --git a/src/min_hftn.h b/src/min_hftn.h
index c96834a50f..891639e2ac 100644
--- a/src/min_hftn.h
+++ b/src/min_hftn.h
@@ -24,17 +24,6 @@ MinimizeStyle(hftn,MinHFTN)
 
 namespace LAMMPS_NS
 {
-  //---- THE ALGORITHM NEEDS TO STORE THIS MANY ATOM-BASED VECTORS,
-  //---- IN ADDITION TO ATOM POSITIONS AND THE FORCE VECTOR.
-
-  static const int  NUM_HFTN_ATOM_BASED_VECTORS = 7;
-  static const int  VEC_XK    = 0;   //-- ATOM POSITIONS AT SUBITER START
-  static const int  VEC_CG_P  = 1;   //-- STEP p IN CG SUBITER
-  static const int  VEC_CG_D  = 2;   //-- DIRECTION d IN CG SUBITER
-  static const int  VEC_CG_HD = 3;   //-- HESSIAN-VECTOR PRODUCT Hd
-  static const int  VEC_CG_R  = 4;   //-- RESIDUAL r IN CG SUBITER
-  static const int  VEC_DIF1  = 5;   //-- FOR FINITE DIFFERENCING
-  static const int  VEC_DIF2  = 6;   //-- FOR FINITE DIFFERENCING
 
 class MinHFTN : public Min
 {
@@ -49,6 +38,19 @@ class MinHFTN : public Min
 
   private:
 
+  //---- THE ALGORITHM NEEDS TO STORE THIS MANY ATOM-BASED VECTORS,
+  //---- IN ADDITION TO ATOM POSITIONS AND THE FORCE VECTOR.
+  enum {
+    VEC_XK=0,   //-- ATOM POSITIONS AT SUBITER START
+    VEC_CG_P,   //-- STEP p IN CG SUBITER
+    VEC_CG_D,   //-- DIRECTION d IN CG SUBITER
+    VEC_CG_HD,  //-- HESSIAN-VECTOR PRODUCT Hd
+    VEC_CG_R,   //-- RESIDUAL r IN CG SUBITER
+    VEC_DIF1,   //-- FOR FINITE DIFFERENCING
+    VEC_DIF2,   //-- FOR FINITE DIFFERENCING
+    NUM_HFTN_ATOM_BASED_VECTORS
+  };
+
   //---- ATOM-BASED STORAGE VECTORS.
   double *   _daAVectors[NUM_HFTN_ATOM_BASED_VECTORS];
   double **  _daExtraAtom[NUM_HFTN_ATOM_BASED_VECTORS];