diff --git a/code/ysolve.f90 b/code/ysolve.f90
index 3efdf14..ae3f5bf 100644
--- a/code/ysolve.f90
+++ b/code/ysolve.f90
@@ -108,6 +108,9 @@
       nd=1 
       CALL d2fnonp(nx,hx,ux(1,:),d2ux(1,:),nd,1) 
 
+      dm = diff
+      where (y1(:,1,1)<(1-cstar)) dm = diff * rvis
+
       DO i=1,nx
        yr=ux(1,i)
        c=1.-yr
@@ -386,6 +389,9 @@
         CALL dfnonp(nx,hx,ux(1:3,:),dux(1:3,:),3,1)
         CALL d2fnonp(nx,hx,ux(3:3,:),d2ux(1,:),1,1)
 
+      dm = diff
+      where (r1(:,1,1)<(1.0-cstar)) dm = diff * rvis
+
         DO i=1,nx
          wrate=pre*ux(3,i)*exp(-ac/(1.+bc*(1.-ux(3,i))))   !wrate
 !         IF ((1.-ux(3,i)).le.c_cut) THEN