diff --git a/dsf/org.eclipse.cdt.examples.dsf/.externalToolBuilders/PreProcessor.launch b/dsf/org.eclipse.cdt.examples.dsf/.externalToolBuilders/PreProcessor.launch
index dbd1fe8affe..cc780d8b8e9 100644
--- a/dsf/org.eclipse.cdt.examples.dsf/.externalToolBuilders/PreProcessor.launch
+++ b/dsf/org.eclipse.cdt.examples.dsf/.externalToolBuilders/PreProcessor.launch
@@ -2,8 +2,13 @@
 <launchConfiguration type="org.eclipse.ant.AntBuilderLaunchConfigurationType">
 <booleanAttribute key="org.eclipse.ant.ui.ATTR_TARGETS_UPDATED" value="true"/>
 <booleanAttribute key="org.eclipse.ant.ui.DEFAULT_VM_INSTALL" value="false"/>
-<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_PATHS"/>
-<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_TYPES"/>
+<stringAttribute key="org.eclipse.debug.core.ATTR_REFRESH_SCOPE" value="${project}"/>
+<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_PATHS">
+<listEntry value="/org.eclipse.cdt.examples.dsf/build_preprocess.xml"/>
+</listAttribute>
+<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_TYPES">
+<listEntry value="1"/>
+</listAttribute>
 <booleanAttribute key="org.eclipse.debug.ui.ATTR_LAUNCH_IN_BACKGROUND" value="false"/>
 <stringAttribute key="org.eclipse.jdt.launching.CLASSPATH_PROVIDER" value="org.eclipse.ant.ui.AntClasspathProvider"/>
 <booleanAttribute key="org.eclipse.jdt.launching.DEFAULT_CLASSPATH" value="true"/>