diff --git a/src/main/org/apache/tools/ant/taskdefs/Zip.java b/src/main/org/apache/tools/ant/taskdefs/Zip.java
index df5bddb86..b9a6540bb 100644
--- a/src/main/org/apache/tools/ant/taskdefs/Zip.java
+++ b/src/main/org/apache/tools/ant/taskdefs/Zip.java
@@ -78,7 +78,7 @@ public class Zip extends MatchingTask {
     private File zipFile;
     private File baseDir;
     private boolean doCompress = true;
-    private boolean doUpdate = true;
+    private boolean doUpdate = false;
     private boolean doFilesonly = false;
     protected String archiveType = "zip";
     // For directories: