diff --git a/common.ant.xml b/common.ant.xml
index a74e13b..49f3865 100755
--- a/common.ant.xml
+++ b/common.ant.xml
@@ -43,7 +43,9 @@
   <property name="gwt.build.jni" location="${gwt.build}/jni" />
   <property name="gwt.build.staging" location="${gwt.build}/staging" />
   <property name="gwt.build.dist" location="${gwt.build}/dist" />
+  <!-- gwt.threadsPerProcessor supercedes gwt.threadCount unless set to 0 --> 
   <property name="gwt.threadsPerProcessor" value="1" />
+  <property name="gwt.threadCount" value="1" />
   <property name="project.build" location="${gwt.build.out}/${project.tail}" />
   <property name="project.lib" location="${gwt.build.lib}/gwt-${ant.project.name}.jar" />
   <property name="project.jni" location="${gwt.build}/${project.tail}" />
diff --git a/user/build.xml b/user/build.xml
index 2ada647..4dfe7e5 100755
--- a/user/build.xml
+++ b/user/build.xml
@@ -439,7 +439,8 @@
     <property.ensure name="distro.built" location="${gwt.dev.staging.jar}"
         message="GWT must be built before performing any tests.  This can be fixed by running ant in the ${gwt.root} directory." />
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!--
         The remote targets must be run sequentially or BrowserManager will queue
         requests, which will cause some tests to timeout while waiting.
@@ -473,7 +474,8 @@
     <property.ensure name="distro.built" location="${gwt.dev.staging.jar}"
         message="GWT must be built before performing any tests.  This can be fixed by running ant in the ${gwt.root} directory." />
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <antcall target="test.dev.htmlunit"/>
       <antcall target="test.emma.htmlunit"/>
       <antcall target="test.web.htmlunit"/>
@@ -488,7 +490,8 @@
       depends="compile, compile.tests"
       description="Run dev-mode tests for this project.">
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!-- disable HtmlUnit until it is reliable
       <antcall target="test.dev.htmlunit"/>
       -->
@@ -504,7 +507,8 @@
       depends="compile, compile.tests"
       description="Run web-mode tests for this project.">
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!-- disable HtmlUnit until it is reliable
       <antcall target="test.web.htmlunit"/>
       -->
@@ -520,7 +524,8 @@
       depends="compile, compile.tests"
       description="Run emma tests for this project.">
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!-- disable HtmlUnit until it is reliable
       <antcall target="test.emma.htmlunit"/>
       -->
@@ -536,7 +541,8 @@
       depends="compile, compile.tests"
       description="Run draft compiled tests for this project.">
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!-- disable HtmlUnit until it is reliable
       <antcall target="test.draft.htmlunit"/>
       -->
@@ -552,7 +558,8 @@
       depends="compile, compile.tests"
       description="Run -XdisableClassMetadata tests for this project.">
     <limit failonerror="true" hours="${test.timeout}">
-    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}">
+    <parallel threadsPerProcessor="${gwt.threadsPerProcessor}"
+        threadCount="${gwt.threadCount}">
       <!-- disable HtmlUnit until it is reliable
       <antcall target="test.web.htmlunit"/>
       -->