diff --git a/src/fix_heat.cpp b/src/fix_heat.cpp
index a253ea618e..dfe1a356a1 100644
--- a/src/fix_heat.cpp
+++ b/src/fix_heat.cpp
@@ -76,7 +76,7 @@ void FixHeat::end_of_step()
   double vcmsq = vcm[0]*vcm[0] + vcm[1]*vcm[1] + vcm[2]*vcm[2];
   double escale = (ke + heat - 0.5*vcmsq*masstotal)/(ke - 0.5*vcmsq*masstotal);
   if (escale < 0.0) error->all("Fix heat kinetic energy went negative");
-  double r = sqrt(escale);
+  r = sqrt(escale);
 
   vsub[0] = (r-1.0) * vcm[0];
   vsub[1] = (r-1.0) * vcm[1];
@@ -89,3 +89,10 @@ void FixHeat::end_of_step()
       v[i][2] = r*v[i][2] - vsub[2];
     }
 }
+
+/* ---------------------------------------------------------------------- */
+
+double FixHeat::compute_scalar()
+{
+  return r;
+}
diff --git a/src/fix_heat.h b/src/fix_heat.h
index f05e3f3bdc..f012605bea 100644
--- a/src/fix_heat.h
+++ b/src/fix_heat.h
@@ -24,10 +24,12 @@ class FixHeat : public Fix {
   int setmask();
   void init();
   void end_of_step();
+  double compute_scalar();
 
  private:
   double heat;
   double masstotal;
+  double r;
 };
 
 }