diff --git a/XenAdmin/Actions/OVFActions/ApplianceAction.cs b/XenAdmin/Actions/OVFActions/ApplianceAction.cs
index 042576517..2795feae5 100644
--- a/XenAdmin/Actions/OVFActions/ApplianceAction.cs
+++ b/XenAdmin/Actions/OVFActions/ApplianceAction.cs
@@ -47,6 +47,7 @@ namespace XenAdmin.Actions.OVFActions
 		protected XenOvfTransportBase m_transportAction;
 
         private const int SLEEP_TIME = 900;
+        private const int MAX_ITERATIONS = 60 * 60 * 24; // seconds in 24 hours
 
 		/// <summary>
 		/// RBAC dependencies needed to import appliance/export an appliance/import disk image.
@@ -114,7 +115,8 @@ namespace XenAdmin.Actions.OVFActions
 
 	    private void TickUntilCompletion()
 	    {
-	        while (!IsCompleted)
+	        int i = 0;
+	        while (!IsCompleted && ++i<MAX_ITERATIONS)
 	        {
 	            OnChanged();
                 Thread.Sleep(SLEEP_TIME);