Index: src/main/java/org/apache/commons/compress/archivers/tar/TarArchiveOutputStream.java
===================================================================
--- src/main/java/org/apache/commons/compress/archivers/tar/TarArchiveOutputStream.java	(revision 1625774)
+++ src/main/java/org/apache/commons/compress/archivers/tar/TarArchiveOutputStream.java	(working copy)
@@ -659,6 +659,9 @@
                 // create a TarEntry for the LongLink, the contents
                 // of which are the link's name
                 TarArchiveEntry longLinkEntry = new TarArchiveEntry(TarConstants.GNU_LONGLINK, linkType);
+                // overwrite the default modification date (new Date()) in the long link entry. It's never
+                // used, but causes identical archives to have different hash values.
+                longLinkEntry.setModTime(0);
 
                 longLinkEntry.setSize(len + 1); // +1 for NUL
                 putArchiveEntry(longLinkEntry);