diff --git a/lucene/build.xml b/lucene/build.xml
index d9fc7c490bf..c87d8480d41 100644
--- a/lucene/build.xml
+++ b/lucene/build.xml
@@ -31,6 +31,7 @@
   <path id="test.classpath">
   	<path refid="classpath"/>
     <path refid="junit-path"/>
+    <path refid="ant-path"/>
     <pathelement location="${build.dir}/classes/test"/>
   </path>
 
@@ -67,6 +68,7 @@
 
   <path id="backwards.test.compile.classpath">
     <path refid="junit-path"/>
+    <path refid="ant-path"/>
     <fileset dir="${backwards.dir}/lib">
       <include name="lucene-core*.jar"/>
     </fileset>
diff --git a/lucene/common-build.xml b/lucene/common-build.xml
index 34dd3fed1d2..abae480a8fd 100644
--- a/lucene/common-build.xml
+++ b/lucene/common-build.xml
@@ -53,6 +53,10 @@
     <pathelement location="${junit-location.jar}"/>
   </path>
 
+  <path id="ant-path">
+    <fileset dir="${common.dir}/lib" includes="ant-*.jar"/>
+  </path>
+
   <!-- default arguments to pass to JVM executing tests -->
   <property name="testmethod" value=""/>
   <property name="args" value=""/>
@@ -81,6 +85,9 @@
   <property name="javac.target" value="1.5"/>
   <property name="javac.source.backwards" value="1.5"/>
   <property name="javac.target.backwards" value="1.5"/>
+  <!-- clover wants to run with -lib, otherwise we prefer a repeatable
+       classpath -->
+  <property name="javac.includeAntRuntime" value="${run.clover}"/>
 
   <property name="javadoc.link" value="http://java.sun.com/j2se/1.5/docs/api/"/>
   <property name="javadoc.access" value="protected"/>
@@ -655,6 +662,7 @@
     <sequential>
       <mkdir dir="@{destdir}"/>
       <javac
+        includeAntRuntime="${javac.includeAntRuntime}"
         encoding="${build.encoding}"
         srcdir="@{srcdir}"
         destdir="@{destdir}"
diff --git a/lucene/contrib/ant/build.xml b/lucene/contrib/ant/build.xml
index 6fb63aac7e0..f68e4a19daf 100644
--- a/lucene/contrib/ant/build.xml
+++ b/lucene/contrib/ant/build.xml
@@ -38,11 +38,30 @@
   <module-uptodate name="analysis/common" jarfile="${common.dir}/../modules/analysis/build/common/lucene-analyzers-common-${version}.jar"
       property="analyzers-common.uptodate" classpath.property="analyzers-common.jar"/>
 
-  <path id="classpath">
+  <path id="common.classpath">
 	 <pathelement path="${analyzers-common.jar}"/>
 	 <path refid="base.classpath"/>
   </path>
 
+  <!-- tricky: we compile against our supported version of ant (ant-path),
+       but because ant's junit task's includeantruntime *does not work at all*,
+       we hack up a custom test classpath that runs against the runtime ant.
+       this is the only way to avoid having two different versions of ant
+       in the classpath -->
+       
+  <path id="classpath">
+     <path refid="common.classpath"/>
+     <path refid="ant-path"/>
+  </path>
+
+  <path id="junit.classpath">
+    <path refid="common.classpath"/>
+    <pathelement location="${common.dir}/build/classes/test"/>
+    <path refid="junit-path"/>
+    <pathelement location="${build.dir}/classes/java"/>
+    <pathelement location="${build.dir}/classes/test"/>
+  </path>
+
   <target name="compile-core" depends="compile-analyzers-common, common.compile-core" />
 
   <target name="compile-analyzers-common" unless="analyzers-common.uptodate">
diff --git a/solr/common-build.xml b/solr/common-build.xml
index 1495a065650..b63ba6e1a54 100644
--- a/solr/common-build.xml
+++ b/solr/common-build.xml
@@ -81,6 +81,10 @@
   <!-- Java Version we are compatible with -->
   <property name="java.compat.version" value="1.6" />
 
+  <!-- clover wants to run with -lib, otherwise we prefer a repeatable
+       classpath -->
+  <property name="javac.includeAntRuntime" value="${run.clover}"/>
+
   <!-- Solr Implementation Version -->
   <!--
        This can be any string value that does not include spaces
@@ -263,6 +267,7 @@
              source="${java.compat.version}"
              debug="on"
              encoding="utf8"
+             includeAntRuntime="${javac.includeAntRuntime}"
              sourcepath=""
              classpathref="@{classpathref}">
          <nested />