diff --git a/lucene/core/src/test/org/apache/lucene/index/TestCompoundFile.java b/lucene/core/src/test/org/apache/lucene/index/TestCompoundFile.java
index d07f271c3e4..704131f5633 100644
--- a/lucene/core/src/test/org/apache/lucene/index/TestCompoundFile.java
+++ b/lucene/core/src/test/org/apache/lucene/index/TestCompoundFile.java
@@ -809,6 +809,11 @@ public class TestCompoundFile extends LuceneTestCase
   
   public void testListAll() throws Exception {
     Directory dir = newDirectory();
+    if (dir instanceof MockDirectoryWrapper) {
+      // test lists files manually and tries to verify every .cfs it finds,
+      // but a virus scanner could leave some trash.
+      ((MockDirectoryWrapper)dir).setEnableVirusScanner(false);
+    }
     // riw should sometimes create docvalues fields, etc
     RandomIndexWriter riw = new RandomIndexWriter(random(), dir);
     Document doc = new Document();