diff --git a/prebuild.xml b/prebuild.xml
index 0b0b25ede3..1dec8835bc 100644
--- a/prebuild.xml
+++ b/prebuild.xml
@@ -1511,6 +1511,7 @@
       <Reference name="OpenSim"/>
       <Reference name="OpenSim.Framework"/>
       <Reference name="OpenSim.Region.Framework"/>
+      <Reference name="OpenSim.Region.ClientStack"/>
       <Reference name="System"/>
       <Reference name="System.Xml"/>
       <Reference name="log4net.dll"/>