diff --git a/vacuum_gambit.p8 b/vacuum_gambit.p8
index 0d1c62c..f8f20d0 100644
--- a/vacuum_gambit.p8
+++ b/vacuum_gambit.p8
@@ -470,7 +470,7 @@ function ship_m:constrain(p, dp, pmin, pmax, want)
  end
  if (bp <= pmax) return want
  -- spread overshoot across frames
- want -= (bp - pmax)/(bf+1)
+ want -= (bp - pmax)/max(bf,1)
  return max(want, -self.thrust)
 end