diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index 33761bbeefe..45ae1814690 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -1175,7 +1175,7 @@
 
 	//Exhale
 	breath.toxins -= gas_breathed
-	breath.oxygen += gas_breathed
+	breath.carbon_dioxide += gas_breathed
 	gas_breathed = 0