diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java
index 56dfa21..a00dd7c 100644
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/rest/change/AbstractSubmit.java
@@ -25,6 +25,7 @@
 import com.google.common.base.Function;
 import com.google.common.base.Strings;
 import com.google.common.collect.HashMultimap;
+import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
@@ -305,6 +306,33 @@
     submit(change1.getChangeId());
   }
 
+  @Test
+  public void submitMergeOfNonChangeBranchTip() throws Exception {
+    // Merge a branch with commits that have not been submitted as
+    // changes.
+    //
+    // M  -- mergeCommit (pushed for review and submitted)
+    // | \
+    // |  S -- stable (pushed directly to refs/heads/stable)
+    // | /
+    // I   -- master
+    //
+    RevCommit master = getRemoteHead(project, "master");
+    PushOneCommit stableTip = pushFactory.create(db, admin.getIdent(), testRepo,
+        "Tip of branch stable", "stable.txt", "");
+    PushOneCommit.Result stable = stableTip.to("refs/heads/stable");
+    PushOneCommit mergeCommit = pushFactory.create(db, admin.getIdent(),
+        testRepo, "The merge commit", "merge.txt", "");
+    mergeCommit.setParents(ImmutableList.of(master, stable.getCommit()));
+    PushOneCommit.Result mergeReview = mergeCommit.to("refs/for/master");
+    approve(mergeReview.getChangeId());
+    submit(mergeReview.getChangeId());
+
+    List<RevCommit> log = getRemoteLog();
+    assertThat(log).contains(stable.getCommit());
+    assertThat(log).contains(mergeReview.getCommit());
+  }
+
   private void assertSubmitter(PushOneCommit.Result change) throws Exception {
     ChangeInfo info = get(change.getChangeId(), ListChangesOption.MESSAGES);
     assertThat(info.messages).isNotNull();
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/RebaseSorter.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/RebaseSorter.java
index be181fa..6cba750 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/RebaseSorter.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/RebaseSorter.java
@@ -32,12 +32,14 @@
   private final CodeReviewRevWalk rw;
   private final RevFlag canMergeFlag;
   private final RevCommit initialTip;
+  private final Set<RevCommit> alreadyAccepted;
 
   public RebaseSorter(CodeReviewRevWalk rw, RevCommit initialTip,
-      RevFlag canMergeFlag) {
+      Set<RevCommit> alreadyAccepted, RevFlag canMergeFlag) {
     this.rw = rw;
     this.canMergeFlag = canMergeFlag;
     this.initialTip = initialTip;
+    this.alreadyAccepted = alreadyAccepted;
   }
 
   public List<CodeReviewCommit> sort(Collection<CodeReviewCommit> incoming)
@@ -57,6 +59,10 @@
       final List<CodeReviewCommit> contents = new ArrayList<>();
       while ((c = rw.next()) != null) {
         if (!c.has(canMergeFlag) || !incoming.contains(c)) {
+          if (isAlreadyMerged(c)) {
+            rw.markUninteresting(c);
+            break;
+          }
           // We cannot merge n as it would bring something we
           // aren't permitted to merge at this time. Drop n.
           //
@@ -82,6 +88,21 @@
     return sorted;
   }
 
+  private boolean isAlreadyMerged(CodeReviewCommit commit) throws IOException {
+    try (CodeReviewRevWalk mirw =
+        CodeReviewCommit.newRevWalk(rw.getObjectReader())) {
+      mirw.reset();
+      mirw.markStart(commit);
+      for (RevCommit accepted : alreadyAccepted) {
+        if (mirw.isMergedInto(mirw.parseCommit(accepted),
+            mirw.parseCommit(commit))) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
   private static <T> T removeOne(final Collection<T> c) {
     final Iterator<T> i = c.iterator();
     final T r = i.next();
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/RebaseIfNecessary.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/RebaseIfNecessary.java
index 4413e26..0bb669b 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/RebaseIfNecessary.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/strategy/RebaseIfNecessary.java
@@ -176,8 +176,8 @@
   private List<CodeReviewCommit> sort(Collection<CodeReviewCommit> toSort,
       RevCommit initialTip) throws IntegrationException {
     try {
-      return new RebaseSorter(
-          args.rw, initialTip, args.canMergeFlag).sort(toSort);
+      return new RebaseSorter(args.rw, initialTip, args.alreadyAccepted,
+          args.canMergeFlag).sort(toSort);
     } catch (IOException e) {
       throw new IntegrationException("Commit sorting failed", e);
     }