diff --git a/mods/ITEMS/mcl_signs/characters b/mods/ITEMS/mcl_signs/characters.txt
similarity index 100%
rename from mods/ITEMS/mcl_signs/characters
rename to mods/ITEMS/mcl_signs/characters.txt
diff --git a/mods/ITEMS/mcl_signs/init.lua b/mods/ITEMS/mcl_signs/init.lua
index 8ae79a5205..f83e63396b 100644
--- a/mods/ITEMS/mcl_signs/init.lua
+++ b/mods/ITEMS/mcl_signs/init.lua
@@ -3,7 +3,7 @@ local S = minetest.get_translator("mcl_signs")
 -- Font: 04.jp.org
 
 -- load characters map
-local chars_file = io.open(minetest.get_modpath("mcl_signs").."/characters", "r")
+local chars_file = io.open(minetest.get_modpath("mcl_signs").."/characters.txt", "r")
 -- FIXME: Support more characters (many characters are missing)
 local charmap = {}
 if not chars_file then