diff --git a/VolZmapVolume.cpp b/VolZmapVolume.cpp
index 1930c68..46cd639 100644
--- a/VolZmapVolume.cpp
+++ b/VolZmapVolume.cpp
@@ -1770,6 +1770,8 @@ VolZmap::Comp_5AxisMilling( int nGrid, const Point3d& ptS, const Point3d& ptE, c
 
    if ( bInverse)
       nTotSurf += 4 ;
+   if ( bSmallMovement)
+      nTotSurf += 2 ;
 
    int nSurfInd = 0 ;
    vector<SurfBezForInters> vSurfBez( nTotSurf) ;