diff --git a/bin/BclExtras.dll b/bin/BclExtras.dll
deleted file mode 100644
index 505cf01f06..0000000000
Binary files a/bin/BclExtras.dll and /dev/null differ
diff --git a/bin/BclExtras35.dll b/bin/BclExtras35.dll
new file mode 100644
index 0000000000..7a7480a3a1
Binary files /dev/null and b/bin/BclExtras35.dll differ
diff --git a/prebuild.xml b/prebuild.xml
index 98a471bb9f..cf0eecca55 100644
--- a/prebuild.xml
+++ b/prebuild.xml
@@ -158,7 +158,7 @@
       <Reference name="System.Data"/>
       <Reference name="System.Drawing"/>
       <Reference name="System.Web"/>
-      <Reference name="BclExtras.dll"/>
+      <Reference name="BclExtras35.dll"/>
       <Reference name="OpenMetaverseTypes.dll"/>
       <Reference name="OpenMetaverse.dll"/>
       <Reference name="OpenMetaverse.StructuredData.dll"/>
@@ -1605,7 +1605,7 @@
       <Reference name="OpenSim.Region.ClientStack"/>
       <Reference name="OpenSim.Region.Physics.Manager"/>
       <Reference name="OpenSim.Services.Interfaces"/>
-      <Reference name="BclExtras.dll"/>
+      <Reference name="BclExtras35.dll"/>
       <Reference name="XMLRPC.dll"/>
       <Reference name="Nini.dll" />
       <Reference name="log4net.dll"/>