diff --git a/code/modules/research/xenobiology/crossbreeding/regenerative.dm b/code/modules/research/xenobiology/crossbreeding/regenerative.dm
index 8e09f4c5707..e42d567342e 100644
--- a/code/modules/research/xenobiology/crossbreeding/regenerative.dm
+++ b/code/modules/research/xenobiology/crossbreeding/regenerative.dm
@@ -244,7 +244,7 @@ Regenerative extracts:
 
 /obj/item/slimecross/regenerative/black/core_effect_before(mob/living/target, mob/user)
 	var/dummytype = target.type
-	if(ismegafauna(target)) //Prevents megafauna duping in a lame way
+	if(target.mob_biotypes & MOB_SPECIAL) //Prevents megafauna and voidwalker duping in a lame way
 		dummytype = /mob/living/basic/slime
 		to_chat(user, span_warning("The milky goo flows over [target], falling into a weak puddle."))
 	var/mob/living/dummy = new dummytype(target.loc)