diff --git a/chameleonic.p8 b/chameleonic.p8
index 6ec1c96..2239968 100644
--- a/chameleonic.p8
+++ b/chameleonic.p8
@@ -1381,7 +1381,7 @@ function rope:_tug(hypothetically)
 
  for i=#ancs-1,2,-1 do
   local ops_before_trash=self:_calc_push(ancs[i+1],ancs[i],ancs[i-1])
-  local ops_after_trash=self:_calc_push(ancs[i+1],ancs[i-1],ancs[i])
+  local ops_after_trash=self:_calc_push(ancs[i-2],ancs[i-1],ancs[i])
   local ops_to_do={}
   if #ops_before_trash>0 then 
    ops_to_do=ops_before_trash 
@@ -1496,6 +1496,7 @@ function rope:_calc_push(
  an,a0,a1
 )
  local ops={}
+ if (an==nil) return ops
  
  if a0.x==a1.x then
   local y0,y1=_mnmx(a0.y,a1.y)