diff --git a/build.xml b/build.xml
index f7b5fd029..c84327d61 100644
--- a/build.xml
+++ b/build.xml
@@ -45,7 +45,7 @@
   <!-- 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="${build.optimize}" deprecation="on" source="1.5" target="1.5">
       <classpath refid="classpath"/>
       <compilerarg value="-Xlint"/>
       <compilerarg value="-Xlint:-serial"/>
@@ -75,7 +75,7 @@
   <!-- build the java class files -->
   <target name="compile" depends="prepare,check-available">
     <javac srcdir="src/java" destdir="${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"/>