diff --git a/code/modules/mob/living/carbon/human/human_damage.dm b/code/modules/mob/living/carbon/human/human_damage.dm
index 16ccf53d7aae0..1f7d1387449b5 100644
--- a/code/modules/mob/living/carbon/human/human_damage.dm
+++ b/code/modules/mob/living/carbon/human/human_damage.dm
@@ -153,7 +153,7 @@
 /mob/living/carbon/human/setOxyLoss(amount)
 	if (!need_breathe())
 		return
-	amount = clamp(amount, 0, 100) / 100
+	amount = (clamp(amount, 0, 100) - getOxyLoss()) / 100
 	adjustOxyLoss(amount * species.total_health)
 
 /mob/living/carbon/human/adjustOxyLoss(amount)