diff --git a/lib/ace/mode/html_highlight_rules.js b/lib/ace/mode/html_highlight_rules.js
index 9c9cc36f..4effa2aa 100644
--- a/lib/ace/mode/html_highlight_rules.js
+++ b/lib/ace/mode/html_highlight_rules.js
@@ -65,7 +65,7 @@ var HtmlHighlightRules = function() {
             include : "tag_whitespace"
         }, {
             token : "entity.other.attribute-name.xml",
-            regex : "[-_a-zA-Z0-9:]+"
+            regex : "[-_a-zA-Z0-9:.]+"
         }, {
             token : "keyword.operator.attribute-equals.xml",
             regex : "=",
@@ -89,7 +89,7 @@ var HtmlHighlightRules = function() {
                 return ["meta.tag.punctuation." + (start == "<" ? "" : "end-") + "tag-open.xml",
                     "meta.tag" + (group ? "." + group : "") + ".tag-name.xml"];
             },
-            regex : "(</?)([-_a-zA-Z0-9:]+)",
+            regex : "(</?)([-_a-zA-Z0-9:.]+)",
             next: "tag_stuff"
         }],
         tag_stuff: [
diff --git a/lib/ace/mode/xml_highlight_rules.js b/lib/ace/mode/xml_highlight_rules.js
index 91da0e70..8e39cae5 100644
--- a/lib/ace/mode/xml_highlight_rules.js
+++ b/lib/ace/mode/xml_highlight_rules.js
@@ -35,8 +35,10 @@ var oop = require("../lib/oop");
 var TextHighlightRules = require("./text_highlight_rules").TextHighlightRules;
 
 var XmlHighlightRules = function(normalize) {
-
-    var tagRegex = "[a-zA-Z][-_a-zA-Z0-9]*";
+    // http://www.w3.org/TR/REC-xml/#NT-NameChar
+	// NameStartChar	   ::=   	":" | [A-Z] | "_" | [a-z] | [#xC0-#xD6] | [#xD8-#xF6] | [#xF8-#x2FF] | [#x370-#x37D] | [#x37F-#x1FFF] | [#x200C-#x200D] | [#x2070-#x218F] | [#x2C00-#x2FEF] | [#x3001-#xD7FF] | [#xF900-#xFDCF] | [#xFDF0-#xFFFD] | [#x10000-#xEFFFF]
+	// NameChar	   ::=   	NameStartChar | "-" | "." | [0-9] | #xB7 | [#x0300-#x036F] | [#x203F-#x2040]
+    var tagRegex = "[_:a-zA-Z\xc0-\uffff][-_:.a-zA-Z0-9\xc0-\uffff]*";
 
     this.$rules = {
         start : [