diff --git a/code/game/turfs/simulated.dm b/code/game/turfs/simulated.dm
index df412dc7c55..e6500518309 100644
--- a/code/game/turfs/simulated.dm
+++ b/code/game/turfs/simulated.dm
@@ -88,13 +88,13 @@
 		if(istype(M, /mob/living/carbon/human))
 			var/mob/living/carbon/human/H = M
 			// Tracking blood
-			var/list/bloodDNA = list()
+			var/list/bloodDNA = null
 			var/bloodcolor=""
 			if(H.shoes)
 				var/obj/item/clothing/shoes/S = H.shoes
 				if(istype(S))
 					S.handle_movement(src,(H.m_intent == "run" ? 1 : 0))
-					if(S.track_blood)
+					if(S.track_blood && S.blood_DNA)
 						bloodDNA = S.blood_DNA
 						bloodcolor=S.blood_color
 						S.track_blood--