diff --git a/src/fix_spring.cpp b/src/fix_spring.cpp
index 14f5f3d02d..bdefcaa938 100644
--- a/src/fix_spring.cpp
+++ b/src/fix_spring.cpp
@@ -38,6 +38,11 @@ FixSpring::FixSpring(LAMMPS *lmp, int narg, char **arg) :
 {
   if (narg < 9) error->all("Illegal fix spring command");
 
+  vector_flag = 1;
+  size_vector = 3;
+  scalar_vector_freq = 1;
+  extensive = 1;
+
   if (strcmp(arg[3],"tether") == 0) {
     if (narg != 9) error->all("Illegal fix spring command");
     styleflag = TETHER;
@@ -147,13 +152,22 @@ void FixSpring::spring_tether()
   double *mass = atom->mass;
   int nlocal = atom->nlocal;
   
+  ftotal[0] = ftotal[1] = ftotal[2] = 0.0;
+  force_flag = 0;
+
   double massfrac;
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
       massfrac = mass[type[i]]/masstotal;
-      f[i][0] -= fx*massfrac;
-      f[i][1] -= fy*massfrac;
-      f[i][2] -= fz*massfrac;
+      fx *= massfrac;
+      fy *= massfrac;
+      fz *= massfrac;
+      f[i][0] -= fx;
+      f[i][1] -= fy;
+      f[i][2] -= fz;
+      ftotal[0] -= fx;
+      ftotal[1] -= fy;
+      ftotal[2] -= fz;
     }
 }
 
@@ -190,7 +204,10 @@ void FixSpring::spring_couple()
   int *type = atom->type;
   double *mass = atom->mass;
   int nlocal = atom->nlocal;
-  
+
+  ftotal[0] = ftotal[1] = ftotal[2] = 0.0;
+  force_flag = 0;
+
   double massfrac;
   for (int i = 0; i < nlocal; i++) {         
     if (mask[i] & groupbit) {
@@ -198,6 +215,9 @@ void FixSpring::spring_couple()
       f[i][0] += fx*massfrac;
       f[i][1] += fy*massfrac;
       f[i][2] += fz*massfrac;
+      ftotal[0] += fx*massfrac;
+      ftotal[1] += fy*massfrac;
+      ftotal[2] += fz*massfrac;
     }
     if (mask[i] & group2bit) {
       massfrac = mass[type[i]]/masstotal2;
@@ -214,3 +234,18 @@ void FixSpring::post_force_respa(int vflag, int ilevel, int iloop)
 {
   if (ilevel == nlevels_respa-1) post_force(vflag);
 }
+
+/* ----------------------------------------------------------------------
+   return components of total spring force on fix group
+------------------------------------------------------------------------- */
+
+double FixSpring::compute_vector(int n)
+{
+  // only sum across procs one time
+
+  if (force_flag == 0) {
+    MPI_Allreduce(ftotal,ftotal_all,3,MPI_DOUBLE,MPI_SUM,world);
+    force_flag = 1;
+  }
+  return ftotal_all[n];
+}
diff --git a/src/fix_spring.h b/src/fix_spring.h
index 2c638bc2e4..66e917cf23 100644
--- a/src/fix_spring.h
+++ b/src/fix_spring.h
@@ -26,6 +26,7 @@ class FixSpring : public Fix {
   void setup();
   void post_force(int);
   void post_force_respa(int, int, int);
+  double compute_vector(int);
 
  private:
   double xc,yc,zc,r0;
@@ -35,6 +36,8 @@ class FixSpring : public Fix {
   int igroup2,group2bit;
   double masstotal,masstotal2;
   int nlevels_respa;
+  double ftotal[3],ftotal_all[3];
+  int force_flag;
 
   void spring_tether();
   void spring_couple();