diff --git a/common/systems/src/buff.rs b/common/systems/src/buff.rs
index 4d9ecb6968..47e3a402fa 100644
--- a/common/systems/src/buff.rs
+++ b/common/systems/src/buff.rs
@@ -744,8 +744,7 @@ fn execute_effect(
             stat.move_speed_multiplier *= 1.0 - *red;
         },
         BuffEffect::PoiseDamageFromLostHealth(strength) => {
-            let lost_health = health.maximum() - health.current();
-            stat.poise_damage_modifier *= 1 + lost_health / 100.0 * *strength;
+            stat.poise_damage_modifier *= 1.0 + (1.0 - health.fraction()) * *strength;
         },
         BuffEffect::AttackDamage(dam) => {
             stat.attack_damage_modifier *= *dam;