diff --git a/cmd/dehub/cmd_commit.go b/cmd/dehub/cmd_commit.go
index f02139c..790d6db 100644
--- a/cmd/dehub/cmd_commit.go
+++ b/cmd/dehub/cmd_commit.go
@@ -167,12 +167,17 @@ func cmdCombine(ctx context.Context, cmd *dcmd.Cmd) {
 		}
 
 		repo := ctxRepo(ctx)
-		ontoBranch := plumbing.NewBranchReferenceName(*onto)
-		gitCommit, err := repo.CombineCommitChanges(
+		commits, err := repo.GetGitRevisionRange(
 			plumbing.Revision(*startRev),
 			plumbing.Revision(*endRev),
-			ontoBranch,
 		)
+		if err != nil {
+			return nil, fmt.Errorf("error getting commits %q to %q: %w",
+				*startRev, *endRev, err)
+		}
+
+		ontoBranch := plumbing.NewBranchReferenceName(*onto)
+		gitCommit, err := repo.CombineCommitChanges(commits, ontoBranch)
 		if err != nil {
 			return nil, err
 		}
diff --git a/commit.go b/commit.go
index e853e35..b8dd8eb 100644
--- a/commit.go
+++ b/commit.go
@@ -180,7 +180,7 @@ func (r *Repo) AccreditCommit(commit Commit, sigInt sigcred.SignifierInterface)
 // required, unless otherwise noted.
 type CommitBareParams struct {
 	Commit     Commit
-	AccountID  string        // used as the author
+	Author     string
 	ParentHash plumbing.Hash // can be zero if the commit has no parents (Q_Q)
 	GitTree    *object.Tree
 }
@@ -195,7 +195,7 @@ func (r *Repo) CommitBare(params CommitBareParams) (GitCommit, error) {
 	}
 
 	author := object.Signature{
-		Name: params.AccountID,
+		Name: params.Author,
 		When: time.Now(),
 	}
 	commit := &object.Commit{
@@ -247,7 +247,7 @@ func (r *Repo) Commit(commit Commit, accountID string) (GitCommit, error) {
 
 	gitCommit, err := r.CommitBare(CommitBareParams{
 		Commit:     commit,
-		AccountID:  accountID,
+		Author:     accountID,
 		ParentHash: headHash,
 		GitTree:    stagedTree,
 	})
diff --git a/commit_change.go b/commit_change.go
index 116b38a..8b005f0 100644
--- a/commit_change.go
+++ b/commit_change.go
@@ -73,30 +73,35 @@ func (cc CommitChange) GetHash() []byte {
 // will return an error, as the change hash which has been accredited in
 // start/end will be different than the one which needs to be accredited in
 // onto/end.
-func (r *Repo) CombineCommitChanges(startRev, endRev plumbing.Revision, onto plumbing.ReferenceName) (GitCommit, error) {
-	startEndCommits, err := r.GetGitRevisionRange(startRev, endRev)
-	if err != nil {
-		return GitCommit{}, fmt.Errorf("retrieving commits %q to %q: %w", startRev, endRev, err)
-	}
-
+func (r *Repo) CombineCommitChanges(commits []GitCommit, onto plumbing.ReferenceName) (GitCommit, error) {
+	authorsSet := map[string]struct{}{}
 	var lastChangeCommit GitCommit
 	var lastChangeCommitOk bool
-	for i := len(startEndCommits) - 1; i >= 0; i-- {
-		if _, lastChangeCommitOk = startEndCommits[i].Interface.(*CommitChange); lastChangeCommitOk {
-			lastChangeCommit = startEndCommits[i]
-			break
+	for _, commit := range commits {
+		if _, ok := commit.Interface.(*CommitChange); ok {
+			lastChangeCommit = commit
+			lastChangeCommitOk = true
+			for _, cred := range commit.Commit.Common.Credentials {
+				authorsSet[cred.AccountID] = struct{}{}
+			}
 		}
 	}
 	if !lastChangeCommitOk {
-		return GitCommit{}, fmt.Errorf("no change commits in range %q to %q", startRev, endRev)
+		return GitCommit{}, errors.New("no change commits in range")
+	}
+
+	authors := make([]string, 0, len(authorsSet))
+	for author := range authorsSet {
+		authors = append(authors, author)
 	}
+	sort.Strings(authors)
 
 	// startTree has to be the tree of startRev, which isn't included in
-	// startEndCommits. Determine it the hard way.
-	startTree, err := r.parentTree(startEndCommits[0].GitCommit)
+	// commits. Determine it the hard way.
+	startTree, err := r.parentTree(commits[0].GitCommit)
 	if err != nil {
-		return GitCommit{}, fmt.Errorf("getting tree of %q (parent of %q): %w",
-			startRev, startEndCommits[0].GitCommit.Hash, err)
+		return GitCommit{}, fmt.Errorf("getting tree of parent of %q: %w",
+			commits[0].GitCommit.Hash, err)
 	}
 
 	msg := lastChangeCommit.Commit.Change.Message
@@ -123,7 +128,7 @@ func (r *Repo) CombineCommitChanges(startRev, endRev plumbing.Revision, onto plu
 	}
 
 	var creds []sigcred.Credential
-	for _, commit := range startEndCommits {
+	for _, commit := range commits {
 		if bytes.Equal(commit.Interface.GetHash(), changeHash) {
 			creds = append(creds, commit.Commit.Common.Credentials...)
 		}
@@ -141,11 +146,10 @@ func (r *Repo) CombineCommitChanges(startRev, endRev plumbing.Revision, onto plu
 		},
 		Common: CommitCommon{Credentials: creds},
 	}
-	accountID := strings.Join(commit.Common.credAccountIDs(), ",")
 
 	gitCommit, err := r.CommitBare(CommitBareParams{
 		Commit:     commit,
-		AccountID:  accountID,
+		Author:     strings.Join(authors, ","),
 		ParentHash: ontoCommit.GitCommit.Hash,
 		GitTree:    endTree,
 	})
diff --git a/commit_change_test.go b/commit_change_test.go
index 032d576..7c12107 100644
--- a/commit_change_test.go
+++ b/commit_change_test.go
@@ -159,11 +159,16 @@ func TestCombineCommitChanges(t *testing.T) {
 		t.Fatal(err)
 	}
 	credCommit := h.tryCommit(true, credCommitObj, h.cfg.Accounts[1].ID, tootSig)
-	combinedCommit, err := h.repo.CombineCommitChanges(
-		plumbing.Revision(tootCommit.GitCommit.Hash.String()),
-		plumbing.Revision(credCommit.GitCommit.Hash.String()),
-		MainRefName,
+
+	allCommits, err := h.repo.GetGitCommitRange(
+		tootCommit.GitCommit.Hash,
+		credCommit.GitCommit.Hash,
 	)
+	if err != nil {
+		t.Fatalf("error getting commits: %v", err)
+	}
+
+	combinedCommit, err := h.repo.CombineCommitChanges(allCommits, MainRefName)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -188,5 +193,7 @@ func TestCombineCommitChanges(t *testing.T) {
 			combinedCommit.GitCommit.Hash, mainHead.GitCommit.Hash)
 	} else if err = h.repo.VerifyCommits(MainRefName, []GitCommit{combinedCommit}); err != nil {
 		t.Fatalf("unable to verify combined commit: %v", err)
+	} else if author := combinedCommit.GitCommit.Author.Name; author != "root" {
+		t.Fatalf("unexpected author value %q", author)
 	}
 }