diff --git a/solr/core/src/java/org/apache/solr/pkg/PackageListeners.java b/solr/core/src/java/org/apache/solr/pkg/PackageListeners.java
index a4835146a1e..b5b295f156f 100644
--- a/solr/core/src/java/org/apache/solr/pkg/PackageListeners.java
+++ b/solr/core/src/java/org/apache/solr/pkg/PackageListeners.java
@@ -23,7 +23,7 @@ import java.lang.ref.SoftReference;
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
-
+import java.util.concurrent.CopyOnWriteArrayList;
 import org.apache.solr.core.PluginInfo;
 import org.apache.solr.core.SolrCore;
 import org.apache.solr.logging.MDCLoggingContext;
@@ -42,7 +42,7 @@ public class PackageListeners {
 
   // this registry only keeps a weak reference because it does not want to
   // cause a memory leak if the listener forgets to unregister itself
-  private List<Reference<Listener>> listeners = new ArrayList<>();
+  private List<Reference<Listener>> listeners = new CopyOnWriteArrayList<>();
 
   public synchronized void addListener(Listener listener) {
     listeners.add(new SoftReference<>(listener));