diff --git a/code/game/mecha/mecha.dm b/code/game/mecha/mecha.dm
index c94c38c6c3..4d24326261 100644
--- a/code/game/mecha/mecha.dm
+++ b/code/game/mecha/mecha.dm
@@ -1574,6 +1574,9 @@
 		return
 	if(href_list["dna_lock"])
 		if(usr != src.occupant)	return
+		if(istype(src, /obj/item/device/mmi/posibrain) || istype(src, /obj/item/device/mmi))
+			src.occupant_message("You are a brain. No.")
+			return
 		if(src.occupant)
 			src.dna = src.occupant.dna.unique_enzymes
 			src.occupant_message("You feel a prick as the needle takes your DNA sample.")