diff --git a/Makefile b/Makefile
index 0a8de2b..ad5061e 100644
--- a/Makefile
+++ b/Makefile
@@ -108,6 +108,7 @@ justinstall: chardef
 
 chardef:
 	texlua tools/make_chardata.lua > make4ht-char-def.lua
+	texlua tools/make_mathmlchardata.lua > make4ht-mathml-char-def.lua
 
 version:
 	echo $(VERSION), $(DATE)
diff --git a/tools/make_mathmlchardata.lua b/tools/make_mathmlchardata.lua
new file mode 100644
index 0000000..7cb99c6
--- /dev/null
+++ b/tools/make_mathmlchardata.lua
@@ -0,0 +1,63 @@
+-- This file generates Lua table with mapping of Unicode charcodes for different math font styles (bold, italic, bold-italic, etc.)
+-- The new version of MathML requires to use different charcodes for different font styles, 
+-- so we need to replace characters in the MathML output depending on the value of the mathvariant attribute.
+
+kpse.set_program_name "luatex"
+local unicode = kpse.find_file("UnicodeData.txt")
+
+local function get_chartype(chartype)
+  -- remove the extra information from the chartype and convert it to the format used in the mathvariant attribute
+  return chartype:gsub("MATHEMATICAL ", "")
+    :gsub("SYMBOL$", "")
+    :gsub("%a+%s*$", "")
+    :gsub("SMALL ", "")
+    :gsub("CAPITAL ", "")
+    :gsub("%s+$", "")
+    :gsub("%s+", "-")
+    :lower()
+end
+
+
+local function parse_unicode(unicode)
+  local unicode_data = {}
+  for line in io.lines(unicode) do
+    -- parse the UnicodeData.txt file to get the base code for the mathematical symbols
+    local code, chartype, basecode = line:match("^(%x+);([^;]+);[^;]+;[^;]+;[^;]+;([^;]+);")
+    -- we are interested only in the mathematical symbols
+    if code and chartype:match("^MATHEMATICAL") then
+      -- the basecode contains extra <font> tag, we need to remove it and convert the hexadecimal number to decimal
+      local base = tonumber(basecode:match("(%x+)$"), 16)
+      -- remove the extra information from the chartype
+      chartype = get_chartype(chartype)
+      local char = tonumber(code, 16)
+      if base and char then
+        -- we need to store corresponding base code for each symbol in the current font style
+        local area = unicode_data[base] or {}
+        area[chartype] = char
+        unicode_data[base] = area
+        -- print("unicode", char, chartype, base)
+      end
+    end
+  end
+  return unicode_data
+end
+
+local unicode_data = parse_unicode(unicode)
+
+print "-- This file is autogenerated from tools/make_mathmlchardata.lua"
+print "return {"
+
+local to_sort = {}
+for base, data in pairs(unicode_data) do
+  local fields = {}
+  for chartype, char in pairs(data) do
+    fields[#fields+1] = string.format("['%s']=%s", chartype, char)
+  end
+  to_sort[#to_sort+1] = string.format("[%05i] = {%s},", base, table.concat(fields, ", "))
+end
+
+-- sort characters
+table.sort(to_sort)
+for _, line in ipairs(to_sort) do print(line) end
+
+print "}"