diff --git a/src/YM/YMhmc.jl b/src/YM/YMhmc.jl
index c3c878a..c973875 100644
--- a/src/YM/YMhmc.jl
+++ b/src/YM/YMhmc.jl
@@ -115,6 +115,9 @@ function MD!(mom, U, int::IntrScheme{NI, T}, lp::SpaceParm, gp::GaugeParm, ymws:
                 else
                     mom .= mom .+ (int.r[k]*ee) .* ymws.frc1
                 end
+                if k == NI
+                    off = -1
+                end
                 k += off
             end
         end