diff --git a/src/fix_bd_sphere.cpp b/src/fix_bd_sphere.cpp
index ba7cd2a81c..cc3c788349 100644
--- a/src/fix_bd_sphere.cpp
+++ b/src/fix_bd_sphere.cpp
@@ -182,9 +182,6 @@ void FixBdSphere::initial_integrate(int /* vflag */)
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
   int d3rot;  // whether to compute angular momentum in xy plane
-
-  dt = update->dt;
-  sqrtdt = sqrt(dt);
   
   if (domain->dimension==2) {
     d3rot = 0;
@@ -315,3 +312,10 @@ void FixBdSphere::post_force(int vflag)
 	}
     }
 }
+
+void FixBdSphere::reset_dt()
+{
+
+  dt = update->dt;
+  sqrtdt = sqrt(dt);
+}
diff --git a/src/fix_bd_sphere.h b/src/fix_bd_sphere.h
index 245e04274e..8a3df214a6 100644
--- a/src/fix_bd_sphere.h
+++ b/src/fix_bd_sphere.h
@@ -33,6 +33,7 @@ class FixBdSphere : public Fix {
   void setup(int);
   void post_force(int);
   int setmask();
+  void reset_dt();
 
  private:
   int seed;               // RNG seed