diff --git a/lualib/lua_magic/heuristics.lua b/lualib/lua_magic/heuristics.lua
index 2571346b4..376e19cd4 100644
--- a/lualib/lua_magic/heuristics.lua
+++ b/lualib/lua_magic/heuristics.lua
@@ -83,7 +83,7 @@ local txt_patterns = {
     {[[^BEGIN:VCARD\r?\n]], 40},
   },
   xml = {
-    {[[(?i)\s*<\?xml\b.+\?>]], 31},
+    {[[<\?xml\b.+\?>]], 31},
   }
 }