diff --git a/code/modules/mob/living/carbon/human/species.dm b/code/modules/mob/living/carbon/human/species.dm
index 12603960136..42b0f040280 100644
--- a/code/modules/mob/living/carbon/human/species.dm
+++ b/code/modules/mob/living/carbon/human/species.dm
@@ -301,10 +301,12 @@ GLOBAL_LIST_EMPTY(roundstart_races)
 		C.Digitigrade_Leg_Swap(TRUE)
 	for(var/X in inherent_traits)
 		C.remove_trait(X, SPECIES_TRAIT)
+
+	//If their inert mutation is not the same, swap it out
 	if((inert_mutation != new_species.inert_mutation) && LAZYLEN(C.dna.mutation_index))
 		C.dna.remove_mutation(inert_mutation)
-		C.dna.mutation_index[C.dna.mutation_index.Find(inert_mutation)] = new_species.inert_mutation
-		C.dna.mutation_index[new_species.inert_mutation] = create_sequence(new_species.inert_mutation)
+		C.dna.add_mutation(new_species.inert_mutation)
+
 	C.remove_movespeed_modifier(MOVESPEED_ID_SPECIES)
 
 	SEND_SIGNAL(C, COMSIG_SPECIES_LOSS, src)