diff --git a/build.xml b/build.xml
index 2f241c33656..e56beaee4fc 100644
--- a/build.xml
+++ b/build.xml
@@ -526,27 +526,43 @@
     </macrodef>
 
     <target name="runtime">
-        <cleandir dir="${output}/classes/runtime"/>
-        <javac2 destdir="${output}/classes/runtime" debug="true" debuglevel="lines,vars,source" includeAntRuntime="false" source="${java.target}" target="${java.target}">
-            <withKotlin/>
-            <src path="${basedir}/core/builtins/src"/>
-            <src path="${basedir}/core/runtime.jvm/src"/>
-        </javac2>
+        <macrodef name="new_kotlinc">
+          <attribute name="src"/>
+          <attribute name="output"/>
+          <attribute name="classpath"/>
 
-        <cleandir dir="${output}/classes/stdlib"/>
-        <java classname="org.jetbrains.jet.cli.jvm.K2JVMCompiler" failonerror="true" fork="true">
-            <classpath>
+          <sequential>
+            <cleandir dir="@{output}"/>
+
+            <java classname="org.jetbrains.jet.cli.jvm.K2JVMCompiler" failonerror="true" fork="true">
+              <classpath>
                 <path refid="classpath"/>
                 <pathelement location="${kotlin-home}/lib/kotlin-compiler.jar"/>
-            </classpath>
-            <arg value="-src"/>
-            <arg value="${basedir}/libraries/stdlib/src"/>
-            <arg value="-output"/>
-            <arg value="${output}/classes/stdlib"/>
-            <arg value="-noStdlib"/>
-            <arg value="-classpath"/>
-            <arg value="${output}/classes/runtime"/>
-        </java>
+              </classpath>
+              <arg value="-src"/>
+              <arg value="@{src}"/>
+              <arg value="-output"/>
+              <arg value="@{output}"/>
+              <arg value="-noStdlib"/>
+              <arg value="-classpath"/>
+              <arg value="@{classpath}"/>
+            </java>
+          </sequential>
+        </macrodef>
+
+        <new_kotlinc src="${basedir}/core/builtins/src${path.separator}${basedir}/core/runtime.jvm/src"
+                     output="${output}/classes/runtime"
+                     classpath="${basedir}/core/builtins/src${path.separator}${basedir}/core/runtime.jvm/src"/>
+
+        <javac2 destdir="${output}/classes/runtime" debug="true" debuglevel="lines,vars,source" includeAntRuntime="false" source="${java.target}" target="${java.target}">
+            <src path="${basedir}/core/builtins/src"/>
+            <src path="${basedir}/core/runtime.jvm/src"/>
+            <classpath location="${output}/classes/runtime"/>
+        </javac2>
+
+        <new_kotlinc src="${basedir}/libraries/stdlib/src"
+                     output="${output}/classes/stdlib"
+                     classpath="${output}/classes/runtime"/>
 
         <jar destfile="${kotlin-home}/lib/kotlin-runtime.jar">
             <fileset dir="${output}/classes/runtime"/>