diff --git a/items.lua b/items.lua
index c23cfb3..e59796c 100644
--- a/items.lua
+++ b/items.lua
@@ -272,7 +272,7 @@ minetest.register_on_player_receive_fields(function(player, name, fields)
             local marker = k:match("marker%-(.+)");
             local pos = player:get_pos();
             if marker or k == "clear_marker" then
-                local player_x, player_z = map:to_coordinates(pos.x, pos.z);
+                local player_x, player_z = map:to_coordinates(pos.x, pos.z, true);
                 map:set_marker(player_x, player_z, marker);
 
                 audio.play_feedback("cartographer_write", player);
diff --git a/map_api.lua b/map_api.lua
index af076f4..5dc2ccc 100644
--- a/map_api.lua
+++ b/map_api.lua
@@ -44,7 +44,7 @@ end
 -- z: The z position, in map coordinates
 -- marker: The marker ID to set, or nil to unset
 function Map.set_marker(self, x, z, marker)
-    if x < self.x or x > self.x + self.w or z < self.z or z > self.z + self.h then
+    if x < 0 or x > self.w or z < 0 or z > self.h then
         return;
     end
 
@@ -64,7 +64,7 @@ end
 --
 -- Returns a marker id
 function Map.get_marker(self, x, z)
-    if x < self.x or x > self.x + self.w or z < self.z or z > self.z + self.h or not self.markers[x] then
+    if x < 0 or x > self.w or z < 0 or z > self.h or not self.markers[x] then
         return nil;
     end