diff --git a/lib/OpenLayers/Feature.js b/lib/OpenLayers/Feature.js
index b56e79eebd..8c65df6ca1 100644
--- a/lib/OpenLayers/Feature.js
+++ b/lib/OpenLayers/Feature.js
@@ -42,7 +42,7 @@ OpenLayers.Feature.prototype= {
         this.layer = layer;
         this.lonlat = lonlat;
         this.data = (data != null) ? data : new Object();
-        this.id = OpenLayers.Util.createUniqueID('Feature_'); 
+        this.id = OpenLayers.Util.createUniqueID(this.CLASS_NAME + "_"); 
     },
 
     /**
diff --git a/lib/OpenLayers/Popup.js b/lib/OpenLayers/Popup.js
index 6e3282ddbd..3a77023dc7 100644
--- a/lib/OpenLayers/Popup.js
+++ b/lib/OpenLayers/Popup.js
@@ -72,7 +72,7 @@ OpenLayers.Popup.prototype = {
         this.opacity = OpenLayers.Popup.OPACITY;
         this.border = OpenLayers.Popup.BORDER;
 
-        this.div = OpenLayers.Util.createDiv(this.id + "_div", null, null, 
+        this.div = OpenLayers.Util.createDiv(this.id, null, null, 
                                              null, null, null, "hidden");
 
         this.events = new OpenLayers.Events(this, this.div, null);