diff --git a/src/fix_add_force.cpp b/src/fix_add_force.cpp
index 4ac65b8bfb..252b450b63 100644
--- a/src/fix_add_force.cpp
+++ b/src/fix_add_force.cpp
@@ -28,9 +28,11 @@ FixAddForce::FixAddForce(LAMMPS *lmp, int narg, char **arg) :
 {
   if (narg != 6) error->all("Illegal fix addforce command");
 
+  scalar_flag = 1;
   vector_flag = 1;
   size_vector = 3;
   scalar_vector_freq = 1;
+  extscalar = 1;
   extvector = 1;
 
   xvalue = atof(arg[3]);
@@ -38,7 +40,7 @@ FixAddForce::FixAddForce(LAMMPS *lmp, int narg, char **arg) :
   zvalue = atof(arg[5]);
 
   force_flag = 0;
-  foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
+  foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -47,6 +49,7 @@ int FixAddForce::setmask()
 {
   int mask = 0;
   mask |= POST_FORCE;
+  mask |= THERMO_ENERGY;
   mask |= POST_FORCE_RESPA;
   mask |= MIN_POST_FORCE;
   return mask;
@@ -84,18 +87,22 @@ void FixAddForce::min_setup(int vflag)
 
 void FixAddForce::post_force(int vflag)
 {
+  double **x = atom->x;
   double **f = atom->f;
   int *mask = atom->mask;
   int nlocal = atom->nlocal;
 
-  foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
+  foriginal[0] = foriginal[1] = foriginal[2] = foriginal[3] = 0.0;
   force_flag = 0;
 
+  // foriginal[0] = - x dot f = "potential" for added force
+
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
-      foriginal[0] += f[i][0];
-      foriginal[1] += f[i][1];
-      foriginal[2] += f[i][2];
+      foriginal[0] -= xvalue*x[i][0] + yvalue*x[i][1] + zvalue[i][2];
+      foriginal[1] += f[i][0];
+      foriginal[2] += f[i][1];
+      foriginal[3] += f[i][2];
       f[i][0] += xvalue;
       f[i][1] += yvalue;
       f[i][2] += zvalue;
@@ -116,6 +123,21 @@ void FixAddForce::min_post_force(int vflag)
   post_force(vflag);
 }
 
+/* ----------------------------------------------------------------------
+   potential energy of added force
+------------------------------------------------------------------------- */
+
+double FixAddForce::compute_scalar()
+{
+  // only sum across procs one time
+
+  if (force_flag == 0) {
+    MPI_Allreduce(foriginal,foriginal_all,4,MPI_DOUBLE,MPI_SUM,world);
+    force_flag = 1;
+  }
+  return foriginal_all[0];
+}
+
 /* ----------------------------------------------------------------------
    return components of total force on fix group before force was changed
 ------------------------------------------------------------------------- */
@@ -125,8 +147,8 @@ double FixAddForce::compute_vector(int n)
   // only sum across procs one time
 
   if (force_flag == 0) {
-    MPI_Allreduce(foriginal,foriginal_all,3,MPI_DOUBLE,MPI_SUM,world);
+    MPI_Allreduce(foriginal,foriginal_all,4,MPI_DOUBLE,MPI_SUM,world);
     force_flag = 1;
   }
-  return foriginal_all[n];
+  return foriginal_all[n+1];
 }
diff --git a/src/fix_add_force.h b/src/fix_add_force.h
index 7b5bd2ec31..52be0c55f8 100644
--- a/src/fix_add_force.h
+++ b/src/fix_add_force.h
@@ -28,11 +28,12 @@ class FixAddForce : public Fix {
   void post_force(int);
   void post_force_respa(int, int, int);
   void min_post_force(int);
+  double compute_scalar();
   double compute_vector(int);
 
  private:
   double xvalue,yvalue,zvalue;
-  double foriginal[3],foriginal_all[3];
+  double foriginal[4],foriginal_all[4];
   int force_flag;
   int nlevels_respa;
 };
diff --git a/src/fix_spring_self.cpp b/src/fix_spring_self.cpp
index 457f9dbcc3..65c2d41b11 100644
--- a/src/fix_spring_self.cpp
+++ b/src/fix_spring_self.cpp
@@ -94,6 +94,7 @@ int FixSpringSelf::setmask()
 {
   int mask = 0;
   mask |= POST_FORCE;
+  mask |= THERMO_ENERGY;
   mask |= POST_FORCE_RESPA;
   mask |= MIN_POST_FORCE;
   return mask;
@@ -122,6 +123,13 @@ void FixSpringSelf::setup(int vflag)
 
 /* ---------------------------------------------------------------------- */
 
+void FixSpringSelf::min_setup(int vflag)
+{
+  post_force(vflag);
+}
+
+/* ---------------------------------------------------------------------- */
+
 void FixSpringSelf::post_force(int vflag)
 {
   double **x = atom->x;
@@ -135,7 +143,7 @@ void FixSpringSelf::post_force(int vflag)
   double zprd = domain->zprd;
   int xbox,ybox,zbox;
   double dx,dy,dz;
-  double espring = 0.0;
+  espring = 0.0;
 
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
@@ -150,6 +158,8 @@ void FixSpringSelf::post_force(int vflag)
       f[i][2] -= k*dz;
       espring += k * (dx*dx + dy*dy + dz*dz);
     }
+
+  espring *= 0.5;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -165,7 +175,6 @@ void FixSpringSelf::post_force_respa(int vflag, int ilevel, int iloop)
 
 double FixSpringSelf::compute_scalar()
 {
-  espring *= 0.5;
   double all;
   MPI_Allreduce(&espring,&all,1,MPI_DOUBLE,MPI_SUM,world);
   return all;
diff --git a/src/fix_spring_self.h b/src/fix_spring_self.h
index d217f0a89b..64dd01cf56 100644
--- a/src/fix_spring_self.h
+++ b/src/fix_spring_self.h
@@ -25,6 +25,7 @@ class FixSpringSelf : public Fix {
   int setmask();
   void init();
   void setup(int);
+  void min_setup(int);
   void post_force(int);
   void post_force_respa(int, int, int);
   void min_post_force(int);