diff --git a/src/mode_merge.f90 b/src/mode_merge.f90
index 2118cff..afc9bba 100644
--- a/src/mode_merge.f90
+++ b/src/mode_merge.f90
@@ -130,8 +130,9 @@ module mode_merge
 
         integer :: i, ibasis, inod
         real(kind=dp), dimension(3) :: current_shift
+        character(len=3) :: alldims
 
-
+        alldims = 'xyz'
         !Calculate the current shift which is the filenum-1 multiplied by the user specified shift
         current_shift = (filenum-1)*shift_vec
 
@@ -154,9 +155,13 @@ module mode_merge
         !If we don't include the wrap command then we have to increase the size of the box
         if(.not.(wrap_flag)) then 
             do i = 1,3
-                if (current_shift(i) < -lim_zero) then 
-                    box_bd(2*i-1) = box_bd(2*i-1) - current_shift(i)
-                else if (current_shift(i) > lim_zero) then 
+                if (alldims(i:i) /= trim(adjustl(dim))) then 
+                    if (current_shift(i) < -lim_zero) then 
+                        box_bd(2*i-1) = box_bd(2*i-1) - current_shift(i)
+                    else if (current_shift(i) > lim_zero) then 
+                        box_bd(2*i) = box_bd(2*i) + current_shift(i)
+                    end if
+                else if (alldims(i:i) == trim(adjustl(dim))) then 
                     box_bd(2*i) = box_bd(2*i) + current_shift(i)
                 end if
             end do