diff --git a/data/core/common.lua b/data/core/common.lua
index 1fc91b8..5bf4f3d 100644
--- a/data/core/common.lua
+++ b/data/core/common.lua
@@ -8,7 +8,7 @@ end
 
 
 function common.utf8_chars(text)
-  return text:gmatch("[\0-\x7f\xc2-\xf4][\x80-\xbf]*")
+  return text:gmatch("[%z\001-\127\194-\244][\128-\191]*")
 end