diff --git a/code/game/objects/items/stacks/stack.dm b/code/game/objects/items/stacks/stack.dm
index d85e615bc1c8..3912e2d64165 100644
--- a/code/game/objects/items/stacks/stack.dm
+++ b/code/game/objects/items/stacks/stack.dm
@@ -182,6 +182,11 @@ Also change the icon to reflect the amount of sheets, if possible.*/
 				to_chat(usr, SPAN_WARNING("The [R.title] cannot be built here!"))  //might cause some friendly fire regarding other items like barbed wire, shouldn't be a problem?
 				return
 
+			var/obj/structure/tunnel/tunnel = locate(/obj/structure/tunnel) in usr.loc
+			if(tunnel)
+				to_chat(usr, SPAN_WARNING("The [R.title] cannot be constructed on a tunnel!"))
+				return
+
 		if((R.flags & RESULT_REQUIRES_SNOW) && !(istype(usr.loc, /turf/open/snow) || istype(usr.loc, /turf/open/auto_turf/snow)))
 			to_chat(usr, SPAN_WARNING("The [R.title] must be built on snow!"))
 			return
diff --git a/code/game/objects/structures/girders.dm b/code/game/objects/structures/girders.dm
index e719359ab439..6cd6a5cd0300 100644
--- a/code/game/objects/structures/girders.dm
+++ b/code/game/objects/structures/girders.dm
@@ -173,6 +173,14 @@
 			return do_reinforced_wall(W, user)
 		if(STATE_DISPLACED)
 			if(HAS_TRAIT(W, TRAIT_TOOL_CROWBAR))
+				var/turf/open/floor = loc
+				if(!floor.allow_construction)
+					to_chat(user, SPAN_WARNING("The girder must be secured on a proper surface!"))
+					return
+				var/obj/structure/tunnel/tunnel = locate(/obj/structure/tunnel) in loc
+				if(tunnel)
+					to_chat(user, SPAN_WARNING("The girder cannot be secured on a tunnel!"))
+					return
 				playsound(loc, 'sound/items/Crowbar.ogg', 25, 1)
 				to_chat(user, SPAN_NOTICE("Now securing the girder..."))
 				if(!do_after(user, 40 * user.get_skill_duration_multiplier(SKILL_CONSTRUCTION), INTERRUPT_ALL|BEHAVIOR_IMMOBILE, BUSY_ICON_BUILD))