diff --git a/code/game/objects/structures/plasticflaps.dm b/code/game/objects/structures/plasticflaps.dm
index 769c04661d..f7eed98f59 100644
--- a/code/game/objects/structures/plasticflaps.dm
+++ b/code/game/objects/structures/plasticflaps.dm
@@ -67,8 +67,11 @@
 	can_atmos_pass = ATMOS_PASS_NO
 
 /obj/structure/plasticflaps/mining/CanPass(atom/A, turf/T)
-	for(var/mob_type in mobs_can_pass)
-		if(istype(A, mob_type))
-			return ..()
-
-	return 0
\ No newline at end of file
+	var/mob/living/M = A
+	if(istype(M))
+		for(var/mob_type in mobs_can_pass)
+			if(istype(A, mob_type))
+				return ..()
+		return 0
+	else
+		return ..()
\ No newline at end of file