diff --git a/mods/carts/cart_entity.lua b/mods/carts/cart_entity.lua
index 8008bcfb..b3b4ae41 100644
--- a/mods/carts/cart_entity.lua
+++ b/mods/carts/cart_entity.lua
@@ -398,7 +398,7 @@ minetest.register_craftitem("carts:cart", {
 				pointed_thing) or itemstack
 		end
 
-		if not pointed_thing.type == "node" then
+		if pointed_thing.type ~= "node" then
 			return
 		end
 		if carts:is_rail(pointed_thing.under) then
diff --git a/mods/doors/init.lua b/mods/doors/init.lua
index 403ad5ab..0c0f0896 100644
--- a/mods/doors/init.lua
+++ b/mods/doors/init.lua
@@ -260,7 +260,7 @@ function doors.register(name, def)
 		on_place = function(itemstack, placer, pointed_thing)
 			local pos
 
-			if not pointed_thing.type == "node" then
+			if pointed_thing.type ~= "node" then
 				return itemstack
 			end
 
diff --git a/mods/player_api/api.lua b/mods/player_api/api.lua
index b3e3f5ee..a80cecb9 100644
--- a/mods/player_api/api.lua
+++ b/mods/player_api/api.lua
@@ -182,7 +182,7 @@ minetest.register_globalstep(function()
 	for _, player in pairs(minetest.get_connected_players()) do
 		local name = player:get_player_name()
 		local player_data = players[name]
-		local model = models[player_data.model]
+		local model = player_data and models[player_data.model]
 		if model and not player_attached[name] then
 			local controls = player:get_player_control()
 			local animation_speed_mod = model.animation_speed or 30
diff --git a/mods/tnt/init.lua b/mods/tnt/init.lua
index 19fe330c..1c4ead33 100644
--- a/mods/tnt/init.lua
+++ b/mods/tnt/init.lua
@@ -243,9 +243,9 @@ local function add_effects(pos, radius, drops)
 			local def = minetest.registered_nodes[name]
 			if def then
 				node = { name = name }
-			end
-			if def and def.tiles and def.tiles[1] then
-				texture = def.tiles[1]
+				if def.tiles and type(def.tiles[1]) == "string" then
+					texture = def.tiles[1]
+				end
 			end
 		end
 	end