diff --git a/src/etc/testcases/taskdefs/zip.xml b/src/etc/testcases/taskdefs/zip.xml
index 02b26a55f..ada643b3e 100644
--- a/src/etc/testcases/taskdefs/zip.xml
+++ b/src/etc/testcases/taskdefs/zip.xml
@@ -260,6 +260,14 @@
     </zip>
   </target>
 
+  <target name="testForBugzilla34764">
+    <mkdir dir="ziptest"/>
+    <touch file="ziptest/file1"/>
+    <zip destfile="test3.zip" basedir="ziptest"/>
+    <touch file="ziptest/file2"/>
+    <zip destfile="test3.zip" basedir="ziptest" update="true"/>
+  </target>
+
   <target name="cleanup">
     <delete file="testLevel.zip"/>
     <delete file="test3.zip"/>
diff --git a/src/tests/junit/org/apache/tools/ant/taskdefs/ZipTest.java b/src/tests/junit/org/apache/tools/ant/taskdefs/ZipTest.java
index 0fc32e658..7d10a927b 100644
--- a/src/tests/junit/org/apache/tools/ant/taskdefs/ZipTest.java
+++ b/src/tests/junit/org/apache/tools/ant/taskdefs/ZipTest.java
@@ -219,4 +219,19 @@ public class ZipTest extends BuildFileTest {
         }
     }
 
+    public void testForBugzilla34764() throws IOException {
+        executeTarget("testForBugzilla34764");
+        org.apache.tools.zip.ZipFile zf = null;
+        try {
+            zf = new org.apache.tools.zip.ZipFile(getProject()
+                                                  .resolveFile("test3.zip"));
+            org.apache.tools.zip.ZipEntry ze = zf.getEntry("file1");
+            assertEquals(UnixStat.FILE_FLAG | 0644, ze.getUnixMode());
+        } finally {
+            if (zf != null) {
+                zf.close();
+            }
+        }
+    }
+
 }