diff --git a/jetty-maven-plugin/src/main/java/org/eclipse/jetty/maven/plugin/JettyWebAppContext.java b/jetty-maven-plugin/src/main/java/org/eclipse/jetty/maven/plugin/JettyWebAppContext.java
index fbd9a36e4ec..e8240e764fa 100644
--- a/jetty-maven-plugin/src/main/java/org/eclipse/jetty/maven/plugin/JettyWebAppContext.java
+++ b/jetty-maven-plugin/src/main/java/org/eclipse/jetty/maven/plugin/JettyWebAppContext.java
@@ -98,7 +98,7 @@ public class JettyWebAppContext extends WebAppContext
     private final List<File> _webInfClasses = new ArrayList<>();
     private final List<File> _webInfJars = new ArrayList<>();
     private final Map<String, File> _webInfJarMap = new HashMap<String, File>();
-    private List<File> _classpathFiles = new ArrayList<>();  //webInfClasses+testClasses+webInfJars
+    private List<File> _classpathFiles; //webInfClasses+testClasses+webInfJars
     private String _jettyEnvXml;
     private List<Overlay> _overlays;
     private Resource _quickStartWebXml;
@@ -413,6 +413,7 @@ public class JettyWebAppContext extends WebAppContext
             _webInfClasses.add(_classes);
         
         // Set up the classpath
+        _classpathFiles = new ArrayList<>();
         _classpathFiles.addAll(_webInfClasses);
         _classpathFiles.addAll(_webInfJars);