diff --git a/GROUPS.md b/GROUPS.md
index c1b6f4eb5..dd95ed501 100644
--- a/GROUPS.md
+++ b/GROUPS.md
@@ -137,6 +137,9 @@ These groups are used mostly for informational purposes
    * `container=4`: Furnace-like, has lists `"src"`, `"fuel"` and `"dst"`.
                     It is expected that this also reacts on `on_timer`;
                     the node timer must be started from other mods when they add into `"src"` or `"fuel"`
+   * `container=5`: Left part of a 2-part horizontal connected container. Both parts have a `"main"` inventory
+                    list. Both inventories are considered to belong together. This is used for large chests.
+   * `container=6`: Same as above, but for the right part.
    * `container=1`: Other/unspecified container type
 * `spawn_egg=1`: Spawn egg
 
diff --git a/mods/ITEMS/mcl_chests/init.lua b/mods/ITEMS/mcl_chests/init.lua
index 661e29764..78a79501b 100644
--- a/mods/ITEMS/mcl_chests/init.lua
+++ b/mods/ITEMS/mcl_chests/init.lua
@@ -146,7 +146,7 @@ minetest.register_node("mcl_chests:"..basename.."_left", {
 	tiles = {"default_chest_top_big.png", "default_chest_top_big.png", "mcl_chests_chest_right.png",
 		"mcl_chests_chest_left.png", "default_chest_side_big.png^[transformFX", "default_chest_front_big.png"},
 	paramtype2 = "facedir",
-	groups = {handy=1,axey=1, container=2,not_in_creative_inventory=1, material_wood=1},
+	groups = {handy=1,axey=1, container=5,not_in_creative_inventory=1, material_wood=1},
 	drop = drop,
 	is_ground_content = false,
 	sounds = mcl_sounds.node_sound_wood_defaults(),
@@ -254,7 +254,7 @@ minetest.register_node("mcl_chests:"..basename.."_right", {
 	tiles = {"default_chest_top_big.png^[transformFX", "default_chest_top_big.png^[transformFX", "mcl_chests_chest_right.png",
 		"mcl_chests_chest_left.png", "default_chest_side_big.png", "default_chest_front_big.png^[transformFX"},
 	paramtype2 = "facedir",
-	groups = {handy=1,axey=1, container=2,not_in_creative_inventory=1, material_wood=1},
+	groups = {handy=1,axey=1, container=6,not_in_creative_inventory=1, material_wood=1},
 	drop = drop,
 	is_ground_content = false,
 	sounds = mcl_sounds.node_sound_wood_defaults(),
diff --git a/mods/ITEMS/mcl_hoppers/init.lua b/mods/ITEMS/mcl_hoppers/init.lua
index ea2aacde7..f7c537b42 100644
--- a/mods/ITEMS/mcl_hoppers/init.lua
+++ b/mods/ITEMS/mcl_hoppers/init.lua
@@ -285,7 +285,7 @@ minetest.register_abm({
 		local upnode = minetest.get_node(uppos)
 		if not minetest.registered_nodes[upnode.name] then return end
 		local g = minetest.registered_nodes[upnode.name].groups.container
-		if g == 2 or g == 3 then
+		if g == 2 or g == 3 or g == 5 or g == 6 then
 			-- Typical container inventory
 			mcl_util.move_item_container(uppos, "main", -1, pos)
 		elseif g == 4 then
@@ -348,17 +348,17 @@ minetest.register_abm({
 		local abovenode = minetest.get_node(above)
 		if not minetest.registered_nodes[abovenode.name] then return end
 		local g = minetest.registered_nodes[abovenode.name].groups.container
-		if g == 2 or g == 3 then
-			-- Typical container inventory
-			mcl_util.move_item_container(above, "main", -1, pos)
-		elseif g == 4 then
+		if g == 4 then
 			-- Furnace output
 			mcl_util.move_item_container(above, "dst", -1, pos)
+		else
+			-- Typical container inventory
+			mcl_util.move_item_container(above, "main", -1, pos)
 		end
 
 		-- Move an item from the hopper into the container to which the hopper points to
 		local g = minetest.registered_nodes[frontnode.name].groups.container
-		if g == 2 then
+		if g == 2 or g == 5 or g == 6 then
 			mcl_util.move_item_container(pos, "main", -1, front)
 		elseif g == 3 then
 			-- Put non-shulker boxes into shulker box