diff --git a/lib/OpenLayers/BaseTypes/Bounds.js b/lib/OpenLayers/BaseTypes/Bounds.js
index f474a45d61..1bbcdd10a5 100644
--- a/lib/OpenLayers/BaseTypes/Bounds.js
+++ b/lib/OpenLayers/BaseTypes/Bounds.js
@@ -459,12 +459,16 @@ OpenLayers.Bounds = OpenLayers.Class({
     transform: function(source, dest) {
         var ll = OpenLayers.Projection.transform(
             {'x': this.left, 'y': this.bottom}, source, dest);
+        var lr = OpenLayers.Projection.transform(
+            {'x': this.right, 'y': this.bottom}, source, dest);
+        var ul = OpenLayers.Projection.transform(
+            {'x': this.left, 'y': this.top}, source, dest);
         var ur = OpenLayers.Projection.transform(
             {'x': this.right, 'y': this.top}, source, dest);
-        this.left   = ll.x;
-        this.bottom = ll.y;
-        this.right  = ur.x;
-        this.top    = ur.y;
+        this.left   = Math.min(ll.x, ul.x);
+        this.bottom = Math.min(ll.y, lr.y);
+        this.right  = Math.max(lr.x, ur.x);
+        this.top    = Math.max(ul.y, ur.y);
         return this;
     },