diff --git a/lib/ace/ext/modelist.js b/lib/ace/ext/modelist.js
index db2d2f80..69aa8972 100644
--- a/lib/ace/ext/modelist.js
+++ b/lib/ace/ext/modelist.js
@@ -159,7 +159,7 @@ var supportedModes = {
     Velocity:    ["vm"],
     Verilog:     ["v|vh|sv|svh"],
     VHDL:        ["vhd|vhdl"],
-    XML:         ["xml|rdf|rss|wsdl|xslt|atom|mathml|mml|xul|xbl"],
+    XML:         ["xml|rdf|rss|wsdl|xslt|atom|mathml|mml|xul|xbl|xaml"],
     XQuery:      ["xq"],
     YAML:        ["yaml|yml"],
     // Add the missing mode "Django" to ext-modelist