diff --git a/build.xml b/build.xml
index dd673352..75e4a27b 100644
--- a/build.xml
+++ b/build.xml
@@ -62,7 +62,7 @@
   <!-- build the java class files -->
   <target name="compile" depends="prepare,compute-builds">
     <javac srcdir="${src.dir}" destdir="${classes.dir}" includeAntRuntime="false"
-           debug="on" optimize="${build.optimize}" source="1.5" target="1.5" encoding="utf-8">
+           debug="on" optimize="${build.optimize}" source="1.6" target="1.5" encoding="utf-8">
       <classpath refid="classpath"/>
       <exclude name="com/samskivert/io/**" unless="build.io"/>
       <exclude name="com/samskivert/jdbc/**" unless="build.jdbc"/>