diff --git a/computer/init.lua b/computer/init.lua
index f43cc8ad..975f04f0 100644
--- a/computer/init.lua
+++ b/computer/init.lua
@@ -1,4 +1,5 @@
-computer = { }
+computer = {}
+screwdriver = screwdriver or {}
 
 computer.register = function (name, def)
 	local nodename = name
diff --git a/fake_fire/init.lua b/fake_fire/init.lua
index b72db191..b336e565 100644
--- a/fake_fire/init.lua
+++ b/fake_fire/init.lua
@@ -1,3 +1,5 @@
+screwdriver = screwdriver or {}
+
 local function start_smoke(pos, node, clicker, chimney)
 	local this_spawner_meta = minetest.get_meta(pos)
 	local id = this_spawner_meta:get_int("smoky")
diff --git a/homedecor/init.lua b/homedecor/init.lua
index 222b8fa6..1c28ce9a 100644
--- a/homedecor/init.lua
+++ b/homedecor/init.lua
@@ -99,7 +99,7 @@ function homedecor.find_ceiling(itemstack, placer, pointed_thing)
 	return isceiling, pos
 end
 
-if screwdriver == nil then screwdriver = {} end
+screwdriver = screwdriver or {}
 
 homedecor.plain_wood = "homedecor_generic_wood_plain.png^"..
 					   "(homedecor_generic_wood_boards_overlay.png^[colorize:#a7682020:100)"
diff --git a/inbox/init.lua b/inbox/init.lua
index 940ec610..7e5867a5 100644
--- a/inbox/init.lua
+++ b/inbox/init.lua
@@ -1,4 +1,5 @@
 local inbox = {}
+screwdriver = screwdriver or {}
 
 minetest.register_craft({
 	output ="inbox:empty",
diff --git a/itemframes/init.lua b/itemframes/init.lua
index 47b4e45f..ac81b713 100644
--- a/itemframes/init.lua
+++ b/itemframes/init.lua
@@ -1,4 +1,5 @@
 local tmp = {}
+screwdriver = screwdriver or {}
 
 minetest.register_entity("itemframes:item",{
 	hp_max = 1,
diff --git a/lrfurn/init.lua b/lrfurn/init.lua
index 416adafd..2d60dabe 100644
--- a/lrfurn/init.lua
+++ b/lrfurn/init.lua
@@ -1,4 +1,5 @@
 lrfurn = {}
+screwdriver = screwdriver or {}
 
 lrfurn.fdir_to_fwd = {
 	{  0,  1 },
diff --git a/plasmascreen/init.lua b/plasmascreen/init.lua
index ab3e059a..839fa1fa 100644
--- a/plasmascreen/init.lua
+++ b/plasmascreen/init.lua
@@ -1,3 +1,5 @@
+screwdriver = screwdriver or {}
+
 minetest.register_node("plasmascreen:stand", {
 	description = "Plasma Screen TV Stand",
 	tiles = {"plasmascreen_back.png"},
@@ -142,6 +144,7 @@ minetest.register_node("plasmascreen:tv_off", {
 	light_source = 10,
 	selection_box = tv_cbox,
 	collision_box = tv_cbox,
+	on_rotate = screwdriver.disallow,
 	groups = {snappy=1, choppy=2, oddly_breakable_by_hand=2, not_in_creative_inventory=1},
 	after_place_node = function(pos, placer, itemstack)
 		if not checkwall(pos) then
diff --git a/signs_lib/init.lua b/signs_lib/init.lua
index 9bf36e23..2654ff13 100644
--- a/signs_lib/init.lua
+++ b/signs_lib/init.lua
@@ -11,12 +11,12 @@
 -- }
 
 signs_lib = {}
+screwdriver = screwdriver or {}
 
-local screwdriver = screwdriver or {}
 signs_lib.wallmounted_rotate = function(pos, node, user, mode, new_param2)
 	if mode ~= screwdriver.ROTATE_AXIS then return false end
 	minetest.swap_node(pos, {name = node.name, param2 = (node.param2 + 1) % 6})
-    for _, v in ipairs(minetest.get_objects_inside_radius(pos, 0.5)) do
+	for _, v in ipairs(minetest.get_objects_inside_radius(pos, 0.5)) do
 		local e = v:get_luaentity()
 		if e and e.name == "signs:text" then
 			v:remove()