diff --git a/platform/util/src/com/intellij/util/io/PersistentHashMap.java b/platform/util/src/com/intellij/util/io/PersistentHashMap.java
index bbffefd7e465..f4bf5e5fc1e7 100644
--- a/platform/util/src/com/intellij/util/io/PersistentHashMap.java
+++ b/platform/util/src/com/intellij/util/io/PersistentHashMap.java
@@ -327,6 +327,7 @@ public class PersistentHashMap<Key, Value> extends PersistentEnumeratorDelegate<
 
   public final boolean processKeysWithExistingMapping(Processor<Key> processor) throws IOException {
     synchronized (myEnumerator) {
+      myAppendCache.clear();
       return myEnumerator.processAllDataObject(processor, new PersistentEnumerator.DataFilter() {
         public boolean accept(final int id) {
           return readValueId(id).address != NULL_ADDR;