diff --git a/vacuum_gambit.p8 b/vacuum_gambit.p8
index e6af347..4df8742 100644
--- a/vacuum_gambit.p8
+++ b/vacuum_gambit.p8
@@ -729,7 +729,7 @@ function segment:should_step(x, y)
   ret = true
  end
  if self.prev_x then
-  local dx0, dy0 = dest_x = self.prev_x - dest_x, self.prev_y - dest_y
+  local dx0, dy0 = self.prev_x - dest_x, self.prev_y - dest_y
   if dx1 * dx1 + dy1 * dy1 > dx0 * dx0 + dy0 * dy0 then
    if self.was_approaching then
     self.was_approaching = false