diff --git a/lib/rexml/parsers/baseparser.rb b/lib/rexml/parsers/baseparser.rb
index f108ea2d32..053ac6441e 100644
--- a/lib/rexml/parsers/baseparser.rb
+++ b/lib/rexml/parsers/baseparser.rb
@@ -32,10 +32,11 @@ module REXML
       EXTENDER = ''      # TODO
 
       NCNAME_STR= "[#{LETTER}_:][-.\w:#{COMBININGCHAR}#{EXTENDER}]*"
+      NCNAME_STR= "[#{LETTER}_:][-[:alnum:]._:#{COMBININGCHAR}#{EXTENDER}]*"
       NAME_STR= "(?:(#{NCNAME_STR}):)?(#{NCNAME_STR})"
       UNAME_STR= "(?:#{NCNAME_STR}:)?#{NCNAME_STR}"
 
-      NAMECHAR = '[\-\w:]'
+      NAMECHAR = '[\-\w\.:]'
       NAME = "([\\w:]#{NAMECHAR}*)"
       NMTOKEN = "(?:#{NAMECHAR})+"
       NMTOKENS = "#{NMTOKEN}(\\s+#{NMTOKEN})*"
diff --git a/lib/rss/parser.rb b/lib/rss/parser.rb
index 1a9e71ea57..c426a187b8 100644
--- a/lib/rss/parser.rb
+++ b/lib/rss/parser.rb
@@ -417,7 +417,7 @@ module RSS
       end
     end
 
-    NAMESPLIT = /^(?:([\w:][-\w\d.]*):)?([\w:][-\w\d.]*)/
+    NAMESPLIT = /^(?:([\w:][-\w.]*):)?([\w:][-\w.]*)/
     def split_name(name)
       name =~ NAMESPLIT
       [$1 || '', $2]