diff --git a/autoplace_tubes.lua b/autoplace_tubes.lua
index 7f47488..0c648e1 100644
--- a/autoplace_tubes.lua
+++ b/autoplace_tubes.lua
@@ -8,7 +8,7 @@ local function in_table(table,element)
 end
 
 local function is_tube(nodename)
-	return in_table(tubenodes,nodename)
+	return in_table(pipeworks.tubenodes,nodename)
 end
 
 if pipeworks == nil then
diff --git a/item_transport.lua b/item_transport.lua
index 93e9580..d20dfc3 100644
--- a/item_transport.lua
+++ b/item_transport.lua
@@ -220,7 +220,7 @@ local function addVect(pos,vect)
 	return {x=pos.x+vect.x,y=pos.y+vect.y,z=pos.z+vect.z}
 end
 
-adjlist={{x=0,y=0,z=1},{x=0,y=0,z=-1},{x=0,y=1,z=0},{x=0,y=-1,z=0},{x=1,y=0,z=0},{x=-1,y=0,z=0}}
+local adjlist={{x=0,y=0,z=1},{x=0,y=0,z=-1},{x=0,y=1,z=0},{x=0,y=-1,z=0},{x=1,y=0,z=0},{x=-1,y=0,z=0}}
 
 local function notvel(tbl,vel)
 	local tbl2={}
diff --git a/tubes.lua b/tubes.lua
index 0faa8f5..1a31971 100644
--- a/tubes.lua
+++ b/tubes.lua
@@ -1,6 +1,6 @@
 -- This file supplies the various kinds of pneumatic tubes
 
-tubenodes={}
+pipeworks.tubenodes={}
 
 minetest.register_alias("pipeworks:tube", "pipeworks:tube_000000")
 
@@ -118,7 +118,7 @@ for zp = 0, 1 do
 		wscale = {x=1,y=1,z=0.01}
 	end
 	
-	table.insert(tubenodes,name.."_"..tname)
+	table.insert(pipeworks.tubenodes,name.."_"..tname)
 	
 	local nodedef={
 		description = tubedesc,