diff --git a/code/modules/mob/living/basic/slime/actions.dm b/code/modules/mob/living/basic/slime/actions.dm
index 2b399e3128c..2995a240a40 100644
--- a/code/modules/mob/living/basic/slime/actions.dm
+++ b/code/modules/mob/living/basic/slime/actions.dm
@@ -142,7 +142,10 @@
 			baby.befriend(slime_friend)
 
 		babies += baby
-		baby.mutation_chance = clamp(mutation_chance+(rand(5,-5)),0,100)
+		if(mutation_chance == 0)
+			baby.mutation_chance = 0
+		else
+			baby.mutation_chance = clamp(mutation_chance+(rand(5,-5)),0,100)
 		SSblackbox.record_feedback("tally", "slime_babies_born", 1, baby.slime_type.colour)
 
 	var/mob/living/basic/slime/new_slime = pick(babies) // slime that the OG slime will move into.