diff --git a/lib/OpenLayers/Layer/Yahoo.js b/lib/OpenLayers/Layer/Yahoo.js
index ab13d3ca47..689b7c3856 100644
--- a/lib/OpenLayers/Layer/Yahoo.js
+++ b/lib/OpenLayers/Layer/Yahoo.js
@@ -59,10 +59,22 @@ OpenLayers.Layer.Yahoo = OpenLayers.Class(
      */
     loadMapObject:function() {
         try { //do not crash! 
-            this.mapObject = new YMap(this.div, this.type);
+            var size = this.getMapObjectSizeFromOLSize(this.map.getSize());
+            this.mapObject = new YMap(this.div, this.type, size);
             this.mapObject.disableKeyControls();
         } catch(e) {}
     },
+
+    /**
+     * Method: onMapResize
+     * 
+     */
+    onMapResize: function() {
+        try {
+            var size = this.getMapObjectSizeFromOLSize(this.map.getSize());
+            this.mapObject.resizeTo(size);
+        } catch(e) {}     
+    },    
     
     
     /** 
@@ -336,6 +348,21 @@ OpenLayers.Layer.Yahoo = OpenLayers.Class(
     getMapObjectPixelFromXY: function(x, y) {
         return new YCoordPoint(x, y);
     },
-
+    
+  // Size
+  
+    /**
+     * APIMethod: getMapObjectSizeFromOLSize
+     * 
+     * Parameters:
+     * olSize - {<OpenLayers.Size>}
+     * 
+     * Return:
+     * {Object} MapObject Size from olSize parameter
+     */
+    getMapObjectSizeFromOLSize: function(olSize) {
+        return new YSize(olSize.w, olSize.h);
+    },
+    
     CLASS_NAME: "OpenLayers.Layer.Yahoo"
 });
diff --git a/tests/Layer/test_Yahoo.html b/tests/Layer/test_Yahoo.html
new file mode 100755
index 0000000000..5ec5978978
--- /dev/null
+++ b/tests/Layer/test_Yahoo.html
@@ -0,0 +1,120 @@
+<html>
+<head>
+  <script src="http://api.maps.yahoo.com/ajaxymap?v=3.0&appid=euzuro-openlayers"></script>
+  <script src="../../lib/OpenLayers.js"></script>
+  <script type="text/javascript"><!--
+    var layer; 
+
+    function test_01_Layer_Yahoo_constructor (t) {
+        t.plan( 4 );
+
+        var tempEventPane = OpenLayers.Layer.EventPane.prototype.initialize;
+        OpenLayers.Layer.EventPane.prototype.initialize = function(name, options) {
+            t.ok(name == g_Name, "EventPane initialize() called with correct name");
+            t.ok(options == g_Options, "EventPane initialize() called with correct options");
+        }
+
+        var tempFixedZoomLevels = OpenLayers.Layer.FixedZoomLevels.prototype.initialize;
+        OpenLayers.Layer.FixedZoomLevels.prototype.initialize = function(name, options) {
+            t.ok(name == g_Name, "FixedZoomLevels initialize() called with correct name");
+            t.ok(options == g_Options, "FixedZoomLevels initialize() called with correct options");
+        }
+
+
+        g_Name = {};
+        g_Options = {};        
+        var l = new OpenLayers.Layer.Yahoo(g_Name, g_Options);
+
+        OpenLayers.Layer.EventPane.prototype.initialize = tempEventPane;
+        OpenLayers.Layer.FixedZoomLevels.prototype.initialize = tempFixedZoomLevels;
+    }
+
+    function test_02_Layer_Yahoo_loadMapObject(t) {
+        t.plan(5);
+        
+        var temp = YMap;
+        YMap = OpenLayers.Class({
+            initialize: function(div, type, size) {
+                t.ok(div == g_Div, "correct div passed to YMap constructor");
+                t.ok(type == g_Type, "correct type passed to YMap constructor");
+                t.ok(size == g_YMapSize, "correct size passed to YMap constructor");
+            },
+            disableKeyControls: function() {
+                t.ok(true, "disableKeyControls called on map object");
+            }
+        });
+        
+        g_Div = {};
+        g_Type = {};
+        g_MapSize = {};
+        g_YMapSize = {};
+        
+        var l = new OpenLayers.Layer.Yahoo();
+        l.div = g_Div;
+        l.type = g_Type;
+        l.map = {
+            'getSize': function() {
+                return g_MapSize;
+            }
+        };
+        l.getMapObjectSizeFromOLSize = function(mapSize) {
+            t.ok(mapSize == g_MapSize, "correctly translating map size from ol to YSize");
+            return g_YMapSize;
+        };
+
+        l.loadMapObject();
+
+        YMap = temp;
+    }    
+
+    function test_03_Layer_Yahoo_onMapResize(t) {
+        t.plan(2);
+        
+        g_MapSize = {};
+        g_YMapSize = {};
+        
+        var l = new OpenLayers.Layer.Yahoo();
+        l.mapObject = {
+            'resizeTo': function(size) {
+                t.ok(size == g_YMapSize, "correct YSize passed to reiszeTo on map object");
+            }
+        }
+        l.map = {
+            'getSize': function() {
+                return g_MapSize;
+            }
+        };
+        l.getMapObjectSizeFromOLSize = function(mapSize) {
+            t.ok(mapSize == g_MapSize, "correctly translating map size from ol to YSize");
+            return g_YMapSize;
+        };
+
+        l.onMapResize();
+    }
+    
+    function test_04_Layer_Yahoo_getMapObjectSizeFromOLSize(t) {
+        t.plan(2);
+        
+        var temp = YSize;
+        YSize = function(w, h) {
+            t.ok(w == g_Size.w, "correct width passed to YSize constructor");
+            t.ok(h == g_Size.h, "correct height passed to YSize constructor");
+        }
+        
+        g_Size = {
+            'w': {},
+            'h': {}
+        };
+        
+        OpenLayers.Layer.Yahoo.prototype.getMapObjectSizeFromOLSize(g_Size);
+
+        YSize = temp;
+    }
+
+  // -->
+  </script>
+</head>
+<body>
+  <div id="map"></div>
+</body>
+</html>
diff --git a/tests/list-tests.html b/tests/list-tests.html
index aad909b016..c8fa8d7528 100644
--- a/tests/list-tests.html
+++ b/tests/list-tests.html
@@ -51,6 +51,7 @@
     <li>Layer/test_TMS.html</li>
     <li>Layer/test_TileCache.html</li>
     <li>Layer/test_Vector.html</li>
+    <li>Layer/test_Yahoo.html</li>
     <li>Layer/test_GML.html</li>
     <li>Layer/test_WrapDateLine.html</li>
     <li>test_Tile.html</li>
