diff --git a/lib/OpenLayers/Format/WMSCapabilities.js b/lib/OpenLayers/Format/WMSCapabilities.js
index b78af25ae8..cee33eb832 100644
--- a/lib/OpenLayers/Format/WMSCapabilities.js
+++ b/lib/OpenLayers/Format/WMSCapabilities.js
@@ -38,7 +38,7 @@ OpenLayers.Format.WMSCapabilities = OpenLayers.Class(OpenLayers.Format.XML, {
      *     this instance.
      */
     initialize: function(options) {
-        OpenLayers.Format.prototype.initialize.apply(this, [options]);
+        OpenLayers.Format.XML.prototype.initialize.apply(this, [options]);
         this.options = options;
     },