diff --git a/lib/OpenLayers/Layer/WMS.js b/lib/OpenLayers/Layer/WMS.js
index 8f26ba2069..a564df6f41 100644
--- a/lib/OpenLayers/Layer/WMS.js
+++ b/lib/OpenLayers/Layer/WMS.js
@@ -54,7 +54,16 @@ OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
      * but some services want it that way. Default false.
      */
     encodeBBOX: false,
- 
+    
+    /** 
+     * APIProperty: noMagic 
+     * {Boolean} If true, the image format will not be automagicaly switched 
+     *     from image/jpeg to image/png or image/gif when using 
+     *     TRANSPARENT=TRUE. Also isBaseLayer will not changed by the  
+     *     constructor. Default false. 
+     */ 
+    noMagic: false,  
+    
     /**
      * Constructor: OpenLayers.Layer.WMS
      * Create a new WMS layer object
@@ -87,7 +96,7 @@ OpenLayers.Layer.WMS = OpenLayers.Class(OpenLayers.Layer.Grid, {
 
 
         //layer is transparent        
-        if (this.params.TRANSPARENT && 
+        if (!this.noMagic && this.params.TRANSPARENT && 
             this.params.TRANSPARENT.toString().toLowerCase() == "true") {
             
             // unless explicitly set in options, make layer an overlay
diff --git a/tests/Layer/WMS.html b/tests/Layer/WMS.html
index 18c9f86977..ee8c743a2d 100644
--- a/tests/Layer/WMS.html
+++ b/tests/Layer/WMS.html
@@ -15,7 +15,7 @@
                    format: 'image/jpeg'};
 
     function test_Layer_WMS_constructor (t) {
-        t.plan( 13 );
+        t.plan( 15 );
 
         var trans_format = "image/png";
         if (OpenLayers.Util.alphaHack()) { trans_format = "image/gif"; } 
@@ -52,6 +52,17 @@
         params.TRANSPARENT = false;
         var layer6 = new OpenLayers.Layer.WMS(name, url, params);
         t.eq(layer6.isBaseLayer, true, "transparency == false, wms is baselayer");
+
+        params.TRANSPARENT = true;
+        var layer7 = new OpenLayers.Layer.WMS(name, url, params, {noMagic: true});
+        t.eq(layer7.params.FORMAT, "image/jpeg", "When using noMagic true image/jpeg will not be automagically switched to image/png or image/gif if transparent");
+
+        params.TRANSPARENT = true;
+        var layer8 = new OpenLayers.Layer.WMS(name, url, params, {noMagic: true});
+        t.eq(layer8.isBaseLayer, true, "When using noMagic then transparent means the wms layer is not automagically changed to not being a baselayer");
+
+        params.TRANSPARENT = false;
+
     }
     
     function test_Layer_WMS_addtile (t) {