diff --git a/autoplace_tubes.lua b/autoplace_tubes.lua
index f7f7eb7..4bb31bc 100644
--- a/autoplace_tubes.lua
+++ b/autoplace_tubes.lua
@@ -28,6 +28,8 @@ end
 
 --a function for determining which side of the node we are on
 local function nodeside(node, tubedir)
+	if not tubedir or not node or not node.param2 then return "back" end
+
     --get a vector pointing back
     local backdir = minetest.facedir_to_dir(node.param2)