diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BundleWriter.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BundleWriter.java
index b513412da..e148bdaed 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/BundleWriter.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/BundleWriter.java
@@ -190,6 +190,7 @@ public class BundleWriter {
 			inc.addAll(include.values());
 			for (final RevCommit r : assume)
 				exc.add(r.getId());
+			packWriter.setDeltaBaseAsOffset(true);
 			packWriter.setThin(exc.size() > 0);
 			packWriter.preparePack(monitor, inc, exc);