diff --git a/build.xml b/build.xml
index 9e437a69..ff00be5d 100644
--- a/build.xml
+++ b/build.xml
@@ -46,8 +46,7 @@
 
   <!-- makes sure our tools are compiled and defines the ant tasks -->
   <target name="preptools" depends="prepare">
-    <taskdef resource="com/threerings/presents/tools.properties"
-             classpath="${libs.dir}/narya-tools-full.jar"/>
+    <taskdef resource="com/threerings/presents/tools.properties" classpathref="classpath"/>
   </target>
 
   <!-- cleans out the intermediate build files -->
diff --git a/etc/libs-incl.xml b/etc/libs-incl.xml
index 9bd6e90f..9d554327 100644
--- a/etc/libs-incl.xml
+++ b/etc/libs-incl.xml
@@ -10,6 +10,7 @@
     <include name="flexTasks.jar"/>
     <include name="guava.jar"/>
     <include name="guice.jar"/>
+    <include name="javassist.jar"/>
     <include name="jsr250-api.jar"/>
     <include name="junit4.jar"/>
     <include name="narya.jar"/>