diff --git a/build.xml b/build.xml
index b118b63e..d4e70c8f 100644
--- a/build.xml
+++ b/build.xml
@@ -130,9 +130,11 @@
     <delete dir="${gwtjar.dir}"/>
   </target>
 
-  <property name="maven.deploy.repo" value="file://${user.home}/.m2/repository"/>
   <target name="maven-deploy" depends="dist,tests" 
           description="Deploys our build artifacts to a Maven repository.">
+    <fail unless="maven.deploy.repo">
+      Must specify Maven repository with -Dmaven.deploy.repo=file://somepath
+    </fail>
     <artifact:deploy file="${deploy.dir}/${lib.name}.jar" uniqueVersion="false">
       <remoteRepository url="${maven.deploy.repo}"/>
       <pom refid="pom"/>