diff --git a/ladder.lua b/ladder.lua
index 5ac872c..7097c72 100644
--- a/ladder.lua
+++ b/ladder.lua
@@ -46,6 +46,17 @@ local rope_ladder_top_def = {
 	},
 	groups = { choppy=2, oddly_breakable_by_hand=1,flammable=2},
 	sounds = default.node_sound_wood_defaults(),
+	
+	on_place = function(itemstack, placer, pointed_thing)
+		if pointed_thing.type == "node" then
+			local target_node = minetest.get_node(pointed_thing.under)
+			local target_def = minetest.registered_nodes[target_node.name]
+			if target_def.walkable == false then
+				return itemstack
+			end
+		end
+		return minetest.item_place(itemstack, placer, pointed_thing)
+	end,
 
 	after_place_node = function(pos, placer)
 		local pos_below = {x=pos.x, y=pos.y-1, z=pos.z}
diff --git a/ropeboxes.lua b/ropeboxes.lua
index 676f1c2..626b158 100644
--- a/ropeboxes.lua
+++ b/ropeboxes.lua
@@ -134,6 +134,17 @@ local function register_rope_block(multiple, max_multiple, name_prefix, node_pre
 		selection_box = {type="regular"},
 		collision_box = {type="regular"},
 		groups = {choppy=2, oddly_breakable_by_hand=1, rope_block = 1},
+		
+		on_place = function(itemstack, placer, pointed_thing)
+			if pointed_thing.type == "node" then
+				local target_node = minetest.get_node(pointed_thing.under)
+				local target_def = minetest.registered_nodes[target_node.name]
+				if target_def.walkable == false then
+					return itemstack
+				end
+			end
+			return minetest.item_place(itemstack, placer, pointed_thing)
+		end,
 	
 		after_place_node = function(pos, placer)
 			local pos_below = {x=pos.x, y=pos.y-1, z=pos.z}