diff --git a/bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/StackDropAgent.java b/bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/StackDropAgent.java
index 181c56e..bbafaf3 100644
--- a/bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/StackDropAgent.java
+++ b/bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/StackDropAgent.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2010 IBM Corporation and others.
+ * Copyright (c) 2010, 2011 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -215,7 +215,7 @@
 			for (CTabItem cti : dropCTF.getItems()) {
 				if (dragCtrl == cti.getControl()) {
 					int itemIndex = dropCTF.indexOf(cti);
-					if (itemIndex <= dropIndex)
+					if (dropIndex > 0 && itemIndex <= dropIndex)
 						dropIndex--;
 				}
 			}