diff --git a/show-pdf-tags/show-pdf-tags.lua b/show-pdf-tags/show-pdf-tags.lua
index ad893a1..f985217 100755
--- a/show-pdf-tags/show-pdf-tags.lua
+++ b/show-pdf-tags/show-pdf-tags.lua
@@ -416,12 +416,19 @@ local function format_subtype(subtype)
   end
 end
 
+local function format_xml_name(s)
+-- %p would include _
+   return s:gsub("([:+(),@%s])",
+                 function (c) return string.format("_x%02X_",c:byte()) end
+		 )
+ end
+
 local function format_subtype_xml(subtype)
   if subtype.namespace then
     return string.format('<%s xmlns="%s"', subtype.subtype,
                   (hide_w3c and subtype.namespace:gsub('http://www.w3.org', 'http://-www.w3.org')) or subtype.namespace)
   else
-    return "<" .. subtype.subtype:gsub(":","_x3A_")
+    return "<" .. format_xml_name(subtype.subtype)
   end
 end
 
@@ -683,7 +690,7 @@ local function print_tree_xml(tree, ctx)
         if follow_rolemap and mapped then
 	  print(indent .. "</" .. mapped.subtype ..">")
 	else
-	  print(indent .. "</" .. subtype.subtype:gsub(":","_x3A_") ..">")
+	  print(indent .. "</" .. format_xml_name(subtype.subtype) ..">")
 	end
         elseif #lines > 0 then
           for i=1, #lines-1 do
@@ -693,7 +700,7 @@ local function print_tree_xml(tree, ctx)
           if follow_rolemap and mapped then
             print(indent .. "</" .. mapped.subtype ..">")
 	  else
-            print(indent .. "</" .. subtype.subtype:gsub(":","_x3A_") ..">")
+            print(indent .. "</" .. format_xml_name(subtype.subtype) ..">")
 	  end
         end
       end