diff --git a/content/treestyletab/treestyletabbrowser.js b/content/treestyletab/treestyletabbrowser.js
index 97c0b0ef..724ea0d0 100644
--- a/content/treestyletab/treestyletabbrowser.js
+++ b/content/treestyletab/treestyletabbrowser.js
@@ -2928,8 +2928,7 @@ TreeStyleTabBrowser.prototype = {
 		info.canDrop = true;
 		info.source = tab;
 		if (tab) {
-			var isCopy = this.isAccelKeyPressed(aEvent) ||
-						(aEvent.dataTransfer && aEvent.dataTransfer.dropEffect == 'copy');
+			var isCopy = this.isCopyAction(aEvent);
 			if (isCopy && 'duplicateTab' in this.mTabBrowser) {
 				info.action |= this.kACTION_DUPLICATE;
 			}
diff --git a/content/treestyletab/treestyletabbrowser_tabbarDNDObserver.js b/content/treestyletab/treestyletabbrowser_tabbarDNDObserver.js
index 81162d48..cbf15ca7 100644
--- a/content/treestyletab/treestyletabbrowser_tabbarDNDObserver.js
+++ b/content/treestyletab/treestyletabbrowser_tabbarDNDObserver.js
@@ -183,7 +183,7 @@ TreeStyleTabBrowserTabbarDNDObserver.prototype = {
 			if (dropAction.action & this.kACTION_NEWTAB) {
 				dt.effectAllowed = dt.dropEffect = (
 					!dropAction.source ? 'link' :
-					sv.isAccelKeyPressed(aEvent) ? 'copy' :
+					sv.isCopyAction(aEvent) ? 'copy' :
 					'move'
 				);
 			}
diff --git a/modules/utils.js b/modules/utils.js
index fc65eb8b..5d7457e6 100644
--- a/modules/utils.js
+++ b/modules/utils.js
@@ -451,6 +451,12 @@ var TreeStyleTabUtils = {
 			(aEvent.ctrlKey || (aEvent.keyCode == Ci.nsIDOMKeyEvent.DOM_VK_CONTROL)) ;
 	},
  
+	isCopyAction : function TSTUtils_isCopyAction(aEvent) 
+	{
+		return this.isAccelKeyPressed(aEvent) ||
+				(aEvent.dataTransfer && aEvent.dataTransfer.dropEffect == 'copy');
+	},
+ 
 	isEventFiredOnClosebox : function TSTUtils_isEventFiredOnClosebox(aEvent) 
 	{
 		return this.evaluateXPath(