diff --git a/WHATSNEW b/WHATSNEW
index 54485a2b8..ce5a822d4 100644
--- a/WHATSNEW
+++ b/WHATSNEW
@@ -82,6 +82,8 @@ Fixed bugs:
 * <property env> will now work on Unices with /bin/env instead of
   /usr/bin/env.  Bugzilla Report 17642.
 
+* <jar index="on"> could include multiple index lists.  Bugzilla 10262.
+
 Other changes:
 --------------
 * Shipped XML parser is now Xerces 2.4.0
diff --git a/src/main/org/apache/tools/ant/taskdefs/Jar.java b/src/main/org/apache/tools/ant/taskdefs/Jar.java
index c3e90e2db..80a2f4ad8 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Jar.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Jar.java
@@ -466,7 +466,7 @@ public class Jar extends Zip {
     }
 
     /**
-     * Overriden from Zip class to deal with manifests
+     * Overriden from Zip class to deal with manifests and index lists.
      */
     protected void zipFile(InputStream is, ZipOutputStream zOut, String vPath,
                            long lastModified, File fromArchive, int mode)
@@ -475,6 +475,10 @@ public class Jar extends Zip {
             if (! doubleFilePass || (doubleFilePass && skipWriting)) {
                 filesetManifest(fromArchive, is);
             }
+        } else if (INDEX_NAME.equalsIgnoreCase(vPath) && index) {
+            log("Warning: selected " + archiveType
+                + " files include a META-INF/INDEX.LIST which will"
+                + " be replaced by a newly generated one.", Project.MSG_WARN);
         } else {
             super.zipFile(is, zOut, vPath, lastModified, fromArchive, mode);
         }