diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index 09312abdde..f108ea2d32 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -31,7 +31,7 @@ module REXML
       COMBININGCHAR = '' # TODO
       EXTENDER = ''      # TODO
 
-      NCNAME_STR= "[#{LETTER}_:][-#{LETTER}#{DIGIT}._:#{COMBININGCHAR}#{EXTENDER}]*"
+      NCNAME_STR= "[#{LETTER}_:][-.\w:#{COMBININGCHAR}#{EXTENDER}]*"
       NAME_STR= "(?:(#{NCNAME_STR}):)?(#{NCNAME_STR})"
       UNAME_STR= "(?:#{NCNAME_STR}:)?#{NCNAME_STR}"