diff --git a/build.xml b/build.xml
index 3f57bd3e..2be97c0f 100644
--- a/build.xml
+++ b/build.xml
@@ -47,7 +47,7 @@
   <!-- makes sure our tools are compiled and defines the ant tasks -->
   <target name="preptools" depends="prepare">
     <javac srcdir="src/java" destdir="${classes.dir}" includeAntRuntime="false"
-           debug="on" optimize="{$build.optimize}" deprecation="on" source="1.5" target="1.5">
+           debug="on" optimize="${build.optimize}" deprecation="on" source="1.5" target="1.5">
       <classpath refid="classpath"/>
       <compilerarg value="-Xlint"/>
       <compilerarg value="-Xlint:-serial"/>
@@ -77,7 +77,7 @@
   <!-- build the java class files -->
   <target name="compile" depends="check-available,prepare">
     <javac srcdir="src/java" destdir="${classes.dir}" includeAntRuntime="false"
-           debug="on" optimize="{$build.optimize}" deprecation="on"
+           debug="on" optimize="${build.optimize}" deprecation="on"
            source="1.5" target="1.5">
       <classpath refid="classpath"/>
       <exclude name="com/threerings/**/tools/xml/**" unless="build.xml"/>