diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
index ca5f4fe61..32d4aac75 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevWalk.java
@@ -1308,6 +1308,18 @@ void carryFlagsImpl(final RevCommit c) {
 			RevCommit.carryFlags(c, carry);
 	}
 
+	/**
+	 * Assume additional commits are shallow (have no parents).
+	 *
+	 * @param ids
+	 *            commits that should be treated as shallow commits, in addition
+	 *            to any commits already known to be shallow by the repository.
+	 */
+	public void assumeShallow(Collection<? extends ObjectId> ids) {
+		for (ObjectId id : ids)
+			lookupCommit(id).parents = RevCommit.NO_PARENTS;
+	}
+
 	void initializeShallowCommits() throws IOException {
 		if (shallowCommitsInitialized)
 			throw new IllegalStateException(
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java b/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
index 0cc6946b1..b007f2b51 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java
@@ -684,6 +684,8 @@ else if (requestValidator instanceof AnyRequestValidator)
 
 			if (depth != 0)
 				processShallow();
+			if (!clientShallowCommits.isEmpty())
+				walk.assumeShallow(clientShallowCommits);
 			sendPack = negotiate();
 		} catch (PackProtocolException err) {
 			reportErrorDuringNegotiate(err.getMessage());
@@ -756,7 +758,7 @@ private void processShallow() throws IOException {
 
 			// Commits not on the boundary which are shallow in the client
 			// need to become unshallowed
-			if (c.getDepth() < depth && clientShallowCommits.contains(c)) {
+			if (c.getDepth() < depth && clientShallowCommits.remove(c)) {
 				unshallowCommits.add(c.copy());
 				pckOut.writeString("unshallow " + c.name()); //$NON-NLS-1$
 			}
@@ -1350,7 +1352,7 @@ private void sendPack(final boolean sideband) throws IOException {
 		try {
 			pw.setIndexDisabled(true);
 			pw.setUseCachedPacks(true);
-			pw.setUseBitmaps(true);
+			pw.setUseBitmaps(depth == 0 && clientShallowCommits.isEmpty());
 			pw.setReuseDeltaCommits(true);
 			pw.setDeltaBaseAsOffset(options.contains(OPTION_OFS_DELTA));
 			pw.setThin(options.contains(OPTION_THIN_PACK));