diff --git a/prebuild.xml b/prebuild.xml
index 0a5c959254..0c20b87435 100644
--- a/prebuild.xml
+++ b/prebuild.xml
@@ -1511,7 +1511,7 @@
       <Reference name="OpenSim.Services.Connectors"/>
       <Reference name="OpenSim.Services.Base"/>
       <Reference name="OpenSim.Services.Interfaces"/>
-      <Reference name="Ionic.Zip"/>
+      <Reference name="Ionic.Zip" path="../../../bin/"/>
 
       <Reference name="GlynnTucker.Cache" path="../../../bin/"/>