diff --git a/code/modules/surgery/organs/tails.dm b/code/modules/surgery/organs/tails.dm
index bd561d42f9..9fd4a337a0 100644
--- a/code/modules/surgery/organs/tails.dm
+++ b/code/modules/surgery/organs/tails.dm
@@ -22,9 +22,10 @@
 /obj/item/organ/tail/cat/Insert(mob/living/carbon/human/H, special = 0, drop_if_replaced = TRUE)
 	..()
 	if(istype(H))
-		H.dna.species.mutant_bodyparts |= "tail_human"
-		H.dna.features["tail_human"] = tail_type
-		H.update_body()
+		if(!("tail_human" in H.dna.species.mutant_bodyparts))
+			H.dna.species.mutant_bodyparts |= "tail_human"
+			H.dna.features["tail_human"] = tail_type
+			H.update_body()
 
 /obj/item/organ/tail/cat/Remove(mob/living/carbon/human/H,  special = 0)
 	..()
@@ -45,10 +46,14 @@
 /obj/item/organ/tail/lizard/Insert(mob/living/carbon/human/H, special = 0, drop_if_replaced = TRUE)
 	..()
 	if(istype(H))
-		H.dna.features["tail_lizard"] = tail_type
-		H.dna.features["spines"] = spines
-		H.dna.species.mutant_bodyparts |= "tail_lizard"
-		H.dna.species.mutant_bodyparts |= "spines"
+		// Checks here are necessary so it wouldn't overwrite the tail of a lizard it spawned in
+		if(!("tail_lizard" in H.dna.species.mutant_bodyparts))
+			H.dna.features["tail_lizard"] = tail_type
+			H.dna.species.mutant_bodyparts |= "tail_lizard"
+
+		if(!("spines" in H.dna.species.mutant_bodyparts))
+			H.dna.features["spines"] = spines
+			H.dna.species.mutant_bodyparts |= "spines"
 		H.update_body()
 
 /obj/item/organ/tail/lizard/Remove(mob/living/carbon/human/H,  special = 0)