diff --git a/lib/OpenLayers/Layer/Grid.js b/lib/OpenLayers/Layer/Grid.js
index 6cbac3b2e9..30021877cb 100644
--- a/lib/OpenLayers/Layer/Grid.js
+++ b/lib/OpenLayers/Layer/Grid.js
@@ -291,15 +291,15 @@ OpenLayers.Layer.Grid = OpenLayers.Class(OpenLayers.Layer.HTTPRequest, {
 
     /**
      * Method: getServerResolution
-     * Return the server-supported resolution that is the closest to
-     *     the resolution passed as a parameter. If no resolution is
-     *     passed the map resolution is used.
+     * Return the closest highest server-supported resolution. Throw an
+     * exception if none is found in the serverResolutions array.
      *
      * Parameters:
-     * resolution - {Number} The base resolution.
+     * resolution - {Number} The base resolution. If undefined the
+     *     map resolution is used.
      *
      * Returns:
-     * {Number} The closest server supported resolution.
+     * {Number} The closest highest server resolution value.
      */
     getServerResolution: function(resolution) {
         resolution = resolution || this.map.getResolution();