diff --git a/lib/libgit2dart.dart b/lib/libgit2dart.dart
index 916aa7f..38c904e 100644
--- a/lib/libgit2dart.dart
+++ b/lib/libgit2dart.dart
@@ -1,3 +1,4 @@
+export 'src/annotated.dart';
 export 'src/blame.dart';
 export 'src/blob.dart';
 export 'src/branch.dart';
diff --git a/lib/src/annotated.dart b/lib/src/annotated.dart
new file mode 100644
index 0000000..b5958f9
--- /dev/null
+++ b/lib/src/annotated.dart
@@ -0,0 +1,102 @@
+import 'dart:ffi';
+
+import 'package:libgit2dart/libgit2dart.dart';
+import 'package:libgit2dart/src/bindings/annotated.dart' as bindings;
+import 'package:libgit2dart/src/bindings/libgit2_bindings.dart';
+
+/// An annotated commit contains information about how it was looked up, which
+/// may be useful for functions like merge or rebase to provide context to the
+/// operation. For example, conflict files will include the name of the source
+/// or target branches being merged.
+class AnnotatedCommit {
+  /// Lookups an annotated commit from the given commit [oid].
+  ///
+  /// It is preferable to use [AnnotatedCommit.fromReference] instead of this
+  /// one, for commit to contain more information about how it was looked up.
+  ///
+  /// **IMPORTANT**: Should be freed to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  AnnotatedCommit.lookup({required Repository repo, required Oid oid}) {
+    _annotatedCommitPointer = bindings.lookup(
+      repoPointer: repo.pointer,
+      oidPointer: oid.pointer,
+    );
+  }
+
+  /// Creates an annotated commit from the given [reference].
+  ///
+  /// **IMPORTANT**: Should be freed to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  AnnotatedCommit.fromReference({
+    required Repository repo,
+    required Reference reference,
+  }) {
+    _annotatedCommitPointer = bindings.fromRef(
+      repoPointer: repo.pointer,
+      referencePointer: reference.pointer,
+    );
+  }
+
+  /// Creates an annotated commit from a revision string.
+  ///
+  /// See `man gitrevisions`, or http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions
+  /// for information on the syntax accepted.
+  ///
+  /// **IMPORTANT**: Should be freed to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  AnnotatedCommit.fromRevSpec({
+    required Repository repo,
+    required String spec,
+  }) {
+    _annotatedCommitPointer = bindings.fromRevSpec(
+      repoPointer: repo.pointer,
+      revspec: spec,
+    );
+  }
+
+  /// Creates an annotated commit from the given fetch head data.
+  ///
+  /// [repo] is repository that contains the given commit.
+  ///
+  /// [branchName] is name of the (remote) branch.
+  ///
+  /// [remoteUrl] is url of the remote.
+  ///
+  /// [oid] is the commit object id of the remote branch.
+  ///
+  /// **IMPORTANT**: Should be freed to release allocated memory.
+  ///
+  /// Throws a [LibGit2Error] if error occured.
+  AnnotatedCommit.fromFetchHead({
+    required Repository repo,
+    required String branchName,
+    required String remoteUrl,
+    required Oid oid,
+  }) {
+    _annotatedCommitPointer = bindings.fromFetchHead(
+      repoPointer: repo.pointer,
+      branchName: branchName,
+      remoteUrl: remoteUrl,
+      oid: oid.pointer,
+    );
+  }
+
+  late final Pointer<git_annotated_commit> _annotatedCommitPointer;
+
+  /// Pointer to pointer to memory address for allocated commit object.
+  Pointer<git_annotated_commit> get pointer => _annotatedCommitPointer;
+
+  /// Commit oid that the given annotated commit refers to.
+  Oid get oid => Oid.fromRaw(bindings.oid(_annotatedCommitPointer).ref);
+
+  /// Reference name that the annotated commit refers to.
+  ///
+  /// Returns empty string if no information found.
+  String get refName => bindings.refName(_annotatedCommitPointer);
+
+  /// Releases memory allocated for commit object.
+  void free() => bindings.free(_annotatedCommitPointer);
+}
diff --git a/lib/src/bindings/annotated.dart b/lib/src/bindings/annotated.dart
new file mode 100644
index 0000000..30bc0d3
--- /dev/null
+++ b/lib/src/bindings/annotated.dart
@@ -0,0 +1,132 @@
+import 'dart:ffi';
+
+import 'package:ffi/ffi.dart';
+import 'package:libgit2dart/src/bindings/libgit2_bindings.dart';
+import 'package:libgit2dart/src/error.dart';
+import 'package:libgit2dart/src/util.dart';
+
+/// Creates an annotated commit from the given commit id. The resulting
+/// annotated commit must be freed with [annotatedFree].
+///
+/// An annotated commit contains information about how it was looked up, which
+/// may be useful for functions like merge or rebase to provide context to the
+/// operation. For example, conflict files will include the name of the source
+/// or target branches being merged. It is therefore preferable to use the most
+/// specific function (e.g. [annotatedFromRef]) instead of this one when that
+/// data is known.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_annotated_commit> lookup({
+  required Pointer<git_repository> repoPointer,
+  required Pointer<git_oid> oidPointer,
+}) {
+  final out = calloc<Pointer<git_annotated_commit>>();
+  final error = libgit2.git_annotated_commit_lookup(
+    out,
+    repoPointer,
+    oidPointer,
+  );
+
+  if (error < 0) {
+    calloc.free(out);
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Creates an annotated commit from the given reference.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_annotated_commit> fromRef({
+  required Pointer<git_repository> repoPointer,
+  required Pointer<git_reference> referencePointer,
+}) {
+  final out = calloc<Pointer<git_annotated_commit>>();
+  final error = libgit2.git_annotated_commit_from_ref(
+    out,
+    repoPointer,
+    referencePointer,
+  );
+
+  if (error < 0) {
+    calloc.free(out);
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Creates an annotated commit from a revision string.
+///
+/// See `man gitrevisions`, or http://git-scm.com/docs/git-rev-parse.html#_specifying_revisions
+/// for information on the syntax accepted.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_annotated_commit> fromRevSpec({
+  required Pointer<git_repository> repoPointer,
+  required String revspec,
+}) {
+  final out = calloc<Pointer<git_annotated_commit>>();
+  final revspecC = revspec.toNativeUtf8().cast<Int8>();
+  final error = libgit2.git_annotated_commit_from_revspec(
+    out,
+    repoPointer,
+    revspecC,
+  );
+
+  calloc.free(revspecC);
+
+  if (error < 0) {
+    calloc.free(out);
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Creates an annotated commit from the given fetch head data.
+///
+/// Throws a [LibGit2Error] if error occured.
+Pointer<git_annotated_commit> fromFetchHead({
+  required Pointer<git_repository> repoPointer,
+  required String branchName,
+  required String remoteUrl,
+  required Pointer<git_oid> oid,
+}) {
+  final out = calloc<Pointer<git_annotated_commit>>();
+  final branchNameC = branchName.toNativeUtf8().cast<Int8>();
+  final remoteUrlC = remoteUrl.toNativeUtf8().cast<Int8>();
+  final error = libgit2.git_annotated_commit_from_fetchhead(
+    out,
+    repoPointer,
+    branchNameC,
+    remoteUrlC,
+    oid,
+  );
+
+  calloc.free(branchNameC);
+  calloc.free(remoteUrlC);
+
+  if (error < 0) {
+    calloc.free(out);
+    throw LibGit2Error(libgit2.git_error_last());
+  } else {
+    return out.value;
+  }
+}
+
+/// Gets the commit ID that the given annotated commit refers to.
+Pointer<git_oid> oid(Pointer<git_annotated_commit> commit) =>
+    libgit2.git_annotated_commit_id(commit);
+
+/// Get the refname that the given annotated commit refers to.
+String refName(Pointer<git_annotated_commit> commit) {
+  final result = libgit2.git_annotated_commit_ref(commit);
+  return result == nullptr ? '' : result.cast<Utf8>().toDartString();
+}
+
+/// Frees an annotated commit.
+void free(Pointer<git_annotated_commit> commit) {
+  libgit2.git_annotated_commit_free(commit);
+}
diff --git a/lib/src/bindings/commit.dart b/lib/src/bindings/commit.dart
index 10d7c0e..1267c96 100644
--- a/lib/src/bindings/commit.dart
+++ b/lib/src/bindings/commit.dart
@@ -25,41 +25,6 @@ Pointer<git_commit> lookup({
   }
 }
 
-/// Creates an annotated commit from the given commit id. The resulting
-/// annotated commit must be freed with [annotatedFree].
-///
-/// An annotated commit contains information about how it was looked up, which
-/// may be useful for functions like merge or rebase to provide context to the
-/// operation. For example, conflict files will include the name of the source
-/// or target branches being merged. It is therefore preferable to use the most
-/// specific function (eg git_annotated_commit_from_ref) instead of this one
-/// when that data is known.
-///
-/// Throws a [LibGit2Error] if error occured.
-Pointer<Pointer<git_annotated_commit>> annotatedLookup({
-  required Pointer<git_repository> repoPointer,
-  required Pointer<git_oid> oidPointer,
-}) {
-  final out = calloc<Pointer<git_annotated_commit>>();
-  final error = libgit2.git_annotated_commit_lookup(
-    out,
-    repoPointer,
-    oidPointer,
-  );
-
-  if (error < 0) {
-    calloc.free(out);
-    throw LibGit2Error(libgit2.git_error_last());
-  } else {
-    return out;
-  }
-}
-
-/// Frees an annotated commit.
-void annotatedFree(Pointer<git_annotated_commit> commit) {
-  libgit2.git_annotated_commit_free(commit);
-}
-
 /// Create new commit in the repository.
 ///
 /// Throws a [LibGit2Error] if error occured.
diff --git a/lib/src/bindings/merge.dart b/lib/src/bindings/merge.dart
index f1ea634..aa256ae 100644
--- a/lib/src/bindings/merge.dart
+++ b/lib/src/bindings/merge.dart
@@ -89,17 +89,20 @@ Pointer<git_oid> mergeBaseOctopus({
 List<int> analysis({
   required Pointer<git_repository> repoPointer,
   required Pointer<git_reference> ourRefPointer,
-  required Pointer<Pointer<git_annotated_commit>> theirHeadPointer,
+  required Pointer<git_annotated_commit> theirHeadPointer,
   required int theirHeadsLen,
 }) {
   final analysisOut = calloc<Int32>();
   final preferenceOut = calloc<Int32>();
+  final theirHead = calloc<Pointer<git_annotated_commit>>();
+  theirHead[0] = theirHeadPointer;
+
   libgit2.git_merge_analysis_for_ref(
     analysisOut,
     preferenceOut,
     repoPointer,
     ourRefPointer,
-    theirHeadPointer,
+    theirHead,
     theirHeadsLen,
   );
 
@@ -107,6 +110,7 @@ List<int> analysis({
 
   calloc.free(analysisOut);
   calloc.free(preferenceOut);
+  calloc.free(theirHead);
 
   return result;
 }
@@ -117,12 +121,15 @@ List<int> analysis({
 /// completes, resolve any conflicts and prepare a commit.
 void merge({
   required Pointer<git_repository> repoPointer,
-  required Pointer<Pointer<git_annotated_commit>> theirHeadsPointer,
+  required Pointer<git_annotated_commit> theirHeadPointer,
   required int theirHeadsLen,
   required int favor,
   required int mergeFlags,
   required int fileFlags,
 }) {
+  final theirHead = calloc<Pointer<git_annotated_commit>>();
+  theirHead[0] = theirHeadPointer;
+
   final mergeOpts = _initMergeOptions(
     favor: favor,
     mergeFlags: mergeFlags,
@@ -138,7 +145,7 @@ void merge({
 
   libgit2.git_merge(
     repoPointer,
-    theirHeadsPointer,
+    theirHead,
     theirHeadsLen,
     mergeOpts,
     checkoutOpts,
@@ -146,6 +153,7 @@ void merge({
 
   calloc.free(mergeOpts);
   calloc.free(checkoutOpts);
+  calloc.free(theirHead);
 }
 
 /// Merge two files as they exist in the in-memory data structures, using the
diff --git a/lib/src/commit.dart b/lib/src/commit.dart
index add02fb..21d9797 100644
--- a/lib/src/commit.dart
+++ b/lib/src/commit.dart
@@ -292,31 +292,3 @@ class Commit {
         ' author: $author}';
   }
 }
-
-/// An annotated commit contains information about how it was looked up, which
-/// may be useful for functions like merge or rebase to provide context to the
-/// operation. For example, conflict files will include the name of the source
-/// or target branches being merged.
-///
-/// Note: for internal use.
-class AnnotatedCommit {
-  /// Lookups an annotated commit from the given commit [oid].
-  ///
-  /// **IMPORTANT**: Should be freed to release allocated memory.
-  ///
-  /// Throws a [LibGit2Error] if error occured.
-  AnnotatedCommit.lookup({required Repository repo, required Oid oid}) {
-    _annotatedCommitPointer = bindings.annotatedLookup(
-      repoPointer: repo.pointer,
-      oidPointer: oid.pointer,
-    );
-  }
-
-  late final Pointer<Pointer<git_annotated_commit>> _annotatedCommitPointer;
-
-  /// Pointer to pointer to memory address for allocated commit object.
-  Pointer<Pointer<git_annotated_commit>> get pointer => _annotatedCommitPointer;
-
-  /// Releases memory allocated for commit object.
-  void free() => bindings.annotatedFree(_annotatedCommitPointer.value);
-}
diff --git a/lib/src/rebase.dart b/lib/src/rebase.dart
index 7754481..f5280f6 100644
--- a/lib/src/rebase.dart
+++ b/lib/src/rebase.dart
@@ -15,44 +15,23 @@ class Rebase {
   /// reachable commits.
   ///
   /// [onto] is the branch to rebase onto, default is to rebase onto the given
-  /// [upstream] (throws if [upstream] is not provided).
+  /// [upstream].
   ///
   /// **IMPORTANT**: Should be freed to release allocated memory.
   ///
   /// Throws a [LibGit2Error] if error occured.
   Rebase.init({
     required Repository repo,
-    Oid? branch,
-    Oid? upstream,
-    Oid? onto,
+    AnnotatedCommit? branch,
+    AnnotatedCommit? upstream,
+    AnnotatedCommit? onto,
   }) {
-    AnnotatedCommit? _branch, _upstream, _onto;
-    if (branch != null) {
-      _branch = AnnotatedCommit.lookup(repo: repo, oid: branch);
-    }
-    if (upstream != null) {
-      _upstream = AnnotatedCommit.lookup(repo: repo, oid: upstream);
-    }
-    if (onto != null) {
-      _onto = AnnotatedCommit.lookup(repo: repo, oid: onto);
-    }
-
     _rebasePointer = bindings.init(
       repoPointer: repo.pointer,
-      branchPointer: _branch?.pointer.value,
-      upstreamPointer: _upstream?.pointer.value,
-      ontoPointer: _onto?.pointer.value,
+      branchPointer: branch?.pointer,
+      upstreamPointer: upstream?.pointer,
+      ontoPointer: onto?.pointer,
     );
-
-    if (branch != null) {
-      _branch!.free();
-    }
-    if (upstream != null) {
-      _upstream!.free();
-    }
-    if (onto != null) {
-      _onto!.free();
-    }
   }
 
   /// Pointer to memory address for allocated rebase object.
diff --git a/lib/src/repository.dart b/lib/src/repository.dart
index 348e15b..736dce0 100644
--- a/lib/src/repository.dart
+++ b/lib/src/repository.dart
@@ -1018,7 +1018,7 @@ class Repository {
     return <Object>[analysisSet, mergePreference];
   }
 
-  /// Merges the given commit [oid] into HEAD, writing the results into the
+  /// Merges the given [commit] into HEAD, writing the results into the
   /// working directory. Any changes are staged for commit and any conflicts
   /// are written to the index. Callers should inspect the repository's index
   /// after this completes, resolve any conflicts and prepare a commit.
@@ -1036,26 +1036,19 @@ class Repository {
   ///
   /// Throws a [LibGit2Error] if error occured.
   void merge({
-    required Oid oid,
+    required AnnotatedCommit commit,
     GitMergeFileFavor favor = GitMergeFileFavor.normal,
     Set<GitMergeFlag> mergeFlags = const {GitMergeFlag.findRenames},
     Set<GitMergeFileFlag> fileFlags = const {GitMergeFileFlag.defaults},
   }) {
-    final theirHead = AnnotatedCommit.lookup(
-      repo: this,
-      oid: oid,
-    );
-
     merge_bindings.merge(
       repoPointer: _repoPointer,
-      theirHeadsPointer: theirHead.pointer,
+      theirHeadPointer: commit.pointer,
       theirHeadsLen: 1,
       favor: favor.value,
       mergeFlags: mergeFlags.fold(0, (acc, e) => acc | e.value),
       fileFlags: fileFlags.fold(0, (acc, e) => acc | e.value),
     );
-
-    theirHead.free();
   }
 
   /// Merges two files as they exist in the in-memory data structures, using the
diff --git a/test/annotated_test.dart b/test/annotated_test.dart
new file mode 100644
index 0000000..fb0a57a
--- /dev/null
+++ b/test/annotated_test.dart
@@ -0,0 +1,118 @@
+import 'dart:ffi';
+import 'dart:io';
+
+import 'package:libgit2dart/libgit2dart.dart';
+import 'package:test/test.dart';
+
+import 'helpers/util.dart';
+
+void main() {
+  late Repository repo;
+  late Directory tmpDir;
+  late Oid tip;
+
+  setUp(() {
+    tmpDir = setupRepo(Directory('test/assets/test_repo/'));
+    repo = Repository.open(tmpDir.path);
+    tip = repo['821ed6e80627b8769d170a293862f9fc60825226'];
+  });
+
+  tearDown(() {
+    repo.free();
+    tmpDir.deleteSync(recursive: true);
+  });
+
+  group('AnnotatedCommit', () {
+    test('lookups annotated commit from provided oid', () {
+      final annotated = AnnotatedCommit.lookup(repo: repo, oid: tip);
+
+      expect(annotated.oid, tip);
+      expect(annotated.refName, '');
+
+      annotated.free();
+    });
+
+    test('throws when trying to lookup annotated commit with invalid oid', () {
+      expect(
+        () => AnnotatedCommit.lookup(repo: repo, oid: repo['0' * 40]),
+        throwsA(isA<LibGit2Error>()),
+      );
+    });
+
+    test('creates annotated commit from provided reference', () {
+      final reference = repo.lookupReference('refs/heads/master');
+      final annotated = AnnotatedCommit.fromReference(
+        repo: repo,
+        reference: reference,
+      );
+
+      expect(annotated.oid, reference.target);
+      expect(annotated.refName, 'refs/heads/master');
+
+      annotated.free();
+      reference.free();
+    });
+
+    test(
+        'throws when trying to create annotated commit from provided '
+        'reference and error occurs', () {
+      final reference = repo.lookupReference('refs/heads/master');
+
+      expect(
+        () => AnnotatedCommit.fromReference(
+          repo: Repository(nullptr),
+          reference: reference,
+        ),
+        throwsA(isA<LibGit2Error>()),
+      );
+
+      reference.free();
+    });
+
+    test('creates annotated commit from provided revspec', () {
+      final annotated = AnnotatedCommit.fromRevSpec(repo: repo, spec: '@{-1}');
+
+      expect(annotated.oid.sha, '5aecfa0fb97eadaac050ccb99f03c3fb65460ad4');
+      expect(annotated.refName, '');
+
+      annotated.free();
+    });
+
+    test('throws when trying to create annotated commit from invalid revspec',
+        () {
+      expect(
+        () => AnnotatedCommit.fromRevSpec(repo: repo, spec: 'invalid'),
+        throwsA(isA<LibGit2Error>()),
+      );
+    });
+
+    test('creates annotated commit from provided fetch head data', () {
+      final oid = repo['821ed6e'];
+      final annotated = AnnotatedCommit.fromFetchHead(
+        repo: repo,
+        branchName: 'master',
+        remoteUrl: 'git://github.com/SkinnyMind/libgit2dart.git',
+        oid: oid,
+      );
+
+      expect(annotated.oid, oid);
+      expect(annotated.refName, 'master');
+
+      annotated.free();
+    });
+
+    test(
+        'throws when trying to create annotated commit from fetch head and '
+        'error occurs', () {
+      expect(
+        () => AnnotatedCommit.fromFetchHead(
+          repo: repo,
+          branchName: '',
+          remoteUrl: '',
+          oid: Oid(nullptr),
+        ),
+        throwsA(isA<LibGit2Error>()),
+      );
+    });
+  });
+}
diff --git a/test/commit_test.dart b/test/commit_test.dart
index c277894..4543498 100644
--- a/test/commit_test.dart
+++ b/test/commit_test.dart
@@ -57,19 +57,6 @@ void main() {
       );
     });
 
-    test('successfully lookups annotated commit for provided oid', () {
-      final annotated = AnnotatedCommit.lookup(repo: repo, oid: tip);
-      expect(annotated, isA<AnnotatedCommit>());
-      annotated.free();
-    });
-
-    test('throws when trying to lookup annotated commit with invalid oid', () {
-      expect(
-        () => AnnotatedCommit.lookup(repo: repo, oid: repo['0' * 40]),
-        throwsA(isA<LibGit2Error>()),
-      );
-    });
-
     test(
         'throws when trying to get the summary of the commit message and error '
         'occurs', () {
diff --git a/test/index_test.dart b/test/index_test.dart
index b247c34..c288444 100644
--- a/test/index_test.dart
+++ b/test/index_test.dart
@@ -311,10 +311,16 @@ void main() {
 
       final conflictBranch = repo.lookupBranch(name: 'conflict-branch');
       final index = repo.index;
-      repo.merge(oid: conflictBranch.target);
+      final commit = AnnotatedCommit.lookup(
+        repo: repo,
+        oid: conflictBranch.target,
+      );
+
+      repo.merge(commit: commit);
 
       expect(() => index.writeTree(), throwsA(isA<LibGit2Error>()));
 
+      commit.free();
       conflictBranch.free();
       index.free();
       repo.free();
@@ -341,10 +347,14 @@ void main() {
       final conflictBranch = conflictRepo.lookupBranch(
         name: 'ancestor-conflict',
       );
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
 
       conflictRepo.checkout(refName: 'refs/heads/feature');
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
 
       final index = conflictRepo.index;
       final conflictedFile = index.conflicts['feature_file']!;
@@ -354,6 +364,7 @@ void main() {
       expect(conflictedFile.toString(), contains('ConflictEntry{'));
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
@@ -364,8 +375,12 @@ void main() {
       final conflictRepo = Repository.open(repoDir.path);
 
       final conflictBranch = conflictRepo.lookupBranch(name: 'conflict-branch');
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
 
       final index = conflictRepo.index;
       final conflictedFile = index.conflicts['conflict_file']!;
@@ -375,6 +390,7 @@ void main() {
       expect(conflictedFile.toString(), contains('ConflictEntry{'));
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
@@ -387,10 +403,14 @@ void main() {
       final conflictBranch = conflictRepo.lookupBranch(
         name: 'ancestor-conflict',
       );
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
 
       conflictRepo.checkout(refName: 'refs/heads/our-conflict');
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
 
       final index = conflictRepo.index;
       final conflictedFile = index.conflicts['feature_file']!;
@@ -400,6 +420,7 @@ void main() {
       expect(conflictedFile.toString(), contains('ConflictEntry{'));
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
@@ -410,10 +431,14 @@ void main() {
       final conflictRepo = Repository.open(repoDir.path);
 
       final conflictBranch = conflictRepo.lookupBranch(name: 'their-conflict');
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
 
       conflictRepo.checkout(refName: 'refs/heads/feature');
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
 
       final index = conflictRepo.index;
       final conflictedFile = index.conflicts['feature_file']!;
@@ -423,6 +448,7 @@ void main() {
       expect(conflictedFile.toString(), contains('ConflictEntry{'));
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
@@ -433,9 +459,13 @@ void main() {
       final conflictRepo = Repository.open(repoDir.path);
 
       final conflictBranch = conflictRepo.lookupBranch(name: 'conflict-branch');
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
       final index = conflictRepo.index;
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
       expect(index.hasConflicts, true);
       expect(index['.gitignore'].isConflict, false);
       expect(index.conflicts['conflict_file']!.our!.isConflict, true);
@@ -448,6 +478,7 @@ void main() {
       expect(index.conflicts['conflict_file'], null);
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
@@ -466,9 +497,13 @@ void main() {
       final conflictRepo = Repository.open(repoDir.path);
 
       final conflictBranch = conflictRepo.lookupBranch(name: 'conflict-branch');
+      final commit = AnnotatedCommit.lookup(
+        repo: conflictRepo,
+        oid: conflictBranch.target,
+      );
       final index = conflictRepo.index;
 
-      conflictRepo.merge(oid: conflictBranch.target);
+      conflictRepo.merge(commit: commit);
       expect(index.hasConflicts, true);
       expect(index.conflicts.length, 1);
 
@@ -477,6 +512,7 @@ void main() {
       expect(index.conflicts, isEmpty);
 
       index.free();
+      commit.free();
       conflictBranch.free();
       conflictRepo.free();
       repoDir.deleteSync(recursive: true);
diff --git a/test/merge_test.dart b/test/merge_test.dart
index 108b6a7..ea6f52a 100644
--- a/test/merge_test.dart
+++ b/test/merge_test.dart
@@ -72,12 +72,16 @@ void main() {
 
     test('writes conflicts to index', () {
       final conflictBranch = repo.lookupBranch(name: 'conflict-branch');
+      final commit = AnnotatedCommit.lookup(
+        repo: repo,
+        oid: conflictBranch.target,
+      );
       final index = repo.index;
 
       final result = repo.mergeAnalysis(theirHead: conflictBranch.target);
       expect(result[0], {GitMergeAnalysis.normal});
 
-      repo.merge(oid: conflictBranch.target);
+      repo.merge(commit: commit);
       expect(index.hasConflicts, true);
       expect(index.conflicts.length, 1);
       expect(repo.state, GitRepositoryState.merge);
@@ -105,6 +109,7 @@ void main() {
       );
 
       index.free();
+      commit.free();
       conflictBranch.free();
     });
 
@@ -118,8 +123,13 @@ conflict branch edit
 >>>>>>> conflict_file
 """;
         final conflictBranch = repo.lookupBranch(name: 'conflict-branch');
+        final commit = AnnotatedCommit.lookup(
+          repo: repo,
+          oid: conflictBranch.target,
+        );
         final index = repo.index;
-        repo.merge(oid: conflictBranch.target);
+
+        repo.merge(commit: commit);
 
         final conflictedFile = index.conflicts['conflict_file']!;
         final diff = repo.mergeFileFromIndex(
@@ -131,6 +141,7 @@ conflict branch edit
         expect(diff, diffExpected);
 
         index.free();
+        commit.free();
         conflictBranch.free();
       });
 
@@ -143,9 +154,14 @@ Another feature edit
 >>>>>>> feature_file
 """;
         final conflictBranch = repo.lookupBranch(name: 'ancestor-conflict');
+        final commit = AnnotatedCommit.lookup(
+          repo: repo,
+          oid: conflictBranch.target,
+        );
         repo.checkout(refName: 'refs/heads/feature');
         final index = repo.index;
-        repo.merge(oid: conflictBranch.target);
+
+        repo.merge(commit: commit);
 
         final conflictedFile = index.conflicts['feature_file']!;
         final diff = repo.mergeFileFromIndex(
@@ -157,6 +173,7 @@ Another feature edit
         expect(diff, diffExpected);
 
         index.free();
+        commit.free();
         conflictBranch.free();
       });
 
@@ -169,9 +186,14 @@ conflict branch edit
 >>>>>>> conflict_file
 """;
         final conflictBranch = repo.lookupBranch(name: 'conflict-branch');
-        final index = repo.index;
-        repo.merge(
+        final commit = AnnotatedCommit.lookup(
+          repo: repo,
           oid: conflictBranch.target,
+        );
+        final index = repo.index;
+
+        repo.merge(
+          commit: commit,
           mergeFlags: {GitMergeFlag.noRecursive},
           fileFlags: {GitMergeFileFlag.ignoreWhitespaceEOL},
         );
@@ -186,14 +208,20 @@ conflict branch edit
         expect(diff, diffExpected);
 
         index.free();
+        commit.free();
         conflictBranch.free();
       });
 
       test('merges with provided merge favor', () {
         final conflictBranch = repo.lookupBranch(name: 'conflict-branch');
+        final commit = AnnotatedCommit.lookup(
+          repo: repo,
+          oid: conflictBranch.target,
+        );
         final index = repo.index;
 
-        repo.merge(oid: conflictBranch.target, favor: GitMergeFileFavor.ours);
+        repo.merge(commit: commit, favor: GitMergeFileFavor.ours);
+
         expect(index.conflicts, isEmpty);
         expect(
           File('${repo.workdir}conflict_file').readAsStringSync(),
@@ -201,6 +229,7 @@ conflict branch edit
         );
 
         index.free();
+        commit.free();
         conflictBranch.free();
       });
 
@@ -274,6 +303,10 @@ theirs content
     group('merge commits', () {
       test('successfully merges with default values', () {
         final theirCommit = repo.lookupCommit(repo['5aecfa0']);
+        final theirCommitAnnotated = AnnotatedCommit.lookup(
+          repo: repo,
+          oid: theirCommit.oid,
+        );
         final ourCommit = repo.lookupCommit(repo['1490545']);
 
         final mergeIndex = repo.mergeCommits(
@@ -283,7 +316,7 @@ theirs content
         expect(mergeIndex.conflicts, isEmpty);
         final mergeCommitsTree = mergeIndex.writeTree(repo);
 
-        repo.merge(oid: theirCommit.oid);
+        repo.merge(commit: theirCommitAnnotated);
         final index = repo.index;
         expect(index.conflicts, isEmpty);
         final mergeTree = index.writeTree();
@@ -293,6 +326,7 @@ theirs content
         index.free();
         mergeIndex.free();
         ourCommit.free();
+        theirCommitAnnotated.free();
         theirCommit.free();
       });
 
@@ -420,6 +454,10 @@ theirs content
     group('merge trees', () {
       test('successfully merges with default values', () {
         final theirCommit = repo.lookupCommit(repo['5aecfa0']);
+        final theirCommitAnnotated = AnnotatedCommit.lookup(
+          repo: repo,
+          oid: theirCommit.oid,
+        );
         final ourCommit = repo.lookupCommit(repo['1490545']);
         final baseCommit = repo.lookupCommit(
           repo.mergeBase([ourCommit.oid, theirCommit.oid]),
@@ -437,7 +475,7 @@ theirs content
         final mergeTreesTree = mergeIndex.writeTree(repo);
 
         repo.setHead(ourCommit.oid);
-        repo.merge(oid: theirCommit.oid);
+        repo.merge(commit: theirCommitAnnotated);
         final index = repo.index;
         expect(index.conflicts, isEmpty);
         final mergeTree = index.writeTree();
@@ -451,6 +489,7 @@ theirs content
         theirTree.free();
         baseCommit.free();
         ourCommit.free();
+        theirCommitAnnotated.free();
         theirCommit.free();
       });
 
diff --git a/test/rebase_test.dart b/test/rebase_test.dart
index 5394a4f..c683800 100644
--- a/test/rebase_test.dart
+++ b/test/rebase_test.dart
@@ -32,15 +32,17 @@ void main() {
         time: 1234,
       );
       final master = repo.lookupReference('refs/heads/master');
+      final branchHead = AnnotatedCommit.lookup(repo: repo, oid: master.target);
       final feature = repo.lookupReference('refs/heads/feature');
+      final ontoHead = AnnotatedCommit.lookup(repo: repo, oid: feature.target);
 
       repo.checkout(refName: feature.name);
       expect(() => repo.index['.gitignore'], throwsA(isA<ArgumentError>()));
 
       final rebase = Rebase.init(
         repo: repo,
-        branch: master.target,
-        onto: feature.target,
+        branch: branchHead,
+        onto: ontoHead,
       );
 
       final operationsCount = rebase.operationsCount;
@@ -63,6 +65,8 @@ void main() {
       expect(repo.index['.gitignore'], isA<IndexEntry>());
 
       rebase.free();
+      ontoHead.free();
+      branchHead.free();
       feature.free();
       master.free();
       signature.free();
@@ -75,10 +79,11 @@ void main() {
         time: 1234,
       );
       final feature = repo.lookupReference('refs/heads/feature');
+      final ontoHead = AnnotatedCommit.lookup(repo: repo, oid: feature.target);
 
       final rebase = Rebase.init(
         repo: repo,
-        onto: feature.target,
+        onto: ontoHead,
       );
 
       final operationsCount = rebase.operationsCount;
@@ -100,6 +105,7 @@ void main() {
       rebase.finish();
 
       rebase.free();
+      ontoHead.free();
       feature.free();
       signature.free();
     });
@@ -111,16 +117,17 @@ void main() {
         time: 1234,
       );
       final master = repo.lookupReference('refs/heads/master');
+      final branchHead = AnnotatedCommit.lookup(repo: repo, oid: master.target);
       final feature = repo.lookupReference('refs/heads/feature');
-      final startCommit = repo.lookupCommit(repo[shas[1]]);
+      final upstream = AnnotatedCommit.lookup(repo: repo, oid: repo[shas[1]]);
 
       repo.checkout(refName: feature.name);
       expect(() => repo.index['conflict_file'], throwsA(isA<ArgumentError>()));
 
       final rebase = Rebase.init(
         repo: repo,
-        branch: master.target,
-        upstream: startCommit.oid,
+        branch: branchHead,
+        upstream: upstream,
       );
 
       final operationsCount = rebase.operationsCount;
@@ -135,7 +142,8 @@ void main() {
       expect(repo.index['conflict_file'], isA<IndexEntry>());
 
       rebase.free();
-      startCommit.free();
+      upstream.free();
+      branchHead.free();
       feature.free();
       master.free();
       signature.free();
@@ -154,14 +162,16 @@ void main() {
         time: 1234,
       );
       final master = repo.lookupReference('refs/heads/master');
+      final branchHead = AnnotatedCommit.lookup(repo: repo, oid: master.target);
       final conflict = repo.lookupReference('refs/heads/conflict-branch');
+      final ontoHead = AnnotatedCommit.lookup(repo: repo, oid: conflict.target);
 
       repo.checkout(refName: conflict.name);
 
       final rebase = Rebase.init(
         repo: repo,
-        branch: master.target,
-        onto: conflict.target,
+        branch: branchHead,
+        onto: ontoHead,
       );
       expect(rebase.operationsCount, 1);
 
@@ -174,6 +184,8 @@ void main() {
       );
 
       rebase.free();
+      ontoHead.free();
+      branchHead.free();
       conflict.free();
       master.free();
       signature.free();
@@ -187,14 +199,16 @@ void main() {
         time: 1234,
       );
       final master = repo.lookupReference('refs/heads/master');
+      final branchHead = AnnotatedCommit.lookup(repo: repo, oid: master.target);
       final conflict = repo.lookupReference('refs/heads/conflict-branch');
+      final ontoHead = AnnotatedCommit.lookup(repo: repo, oid: conflict.target);
 
       repo.checkout(refName: conflict.name);
 
       final rebase = Rebase.init(
         repo: repo,
-        branch: master.target,
-        onto: conflict.target,
+        branch: branchHead,
+        onto: ontoHead,
       );
       expect(rebase.operationsCount, 1);
 
@@ -202,6 +216,8 @@ void main() {
       expect(() => rebase.next(), throwsA(isA<LibGit2Error>()));
 
       rebase.free();
+      ontoHead.free();
+      branchHead.free();
       conflict.free();
       master.free();
       signature.free();
@@ -209,14 +225,16 @@ void main() {
 
     test('successfully aborts rebase in progress', () {
       final master = repo.lookupReference('refs/heads/master');
+      final branchHead = AnnotatedCommit.lookup(repo: repo, oid: master.target);
       final conflict = repo.lookupReference('refs/heads/conflict-branch');
+      final ontoHead = AnnotatedCommit.lookup(repo: repo, oid: conflict.target);
 
       repo.checkout(refName: conflict.name);
 
       final rebase = Rebase.init(
         repo: repo,
-        branch: master.target,
-        onto: conflict.target,
+        branch: branchHead,
+        onto: ontoHead,
       );
       expect(rebase.operationsCount, 1);
 
@@ -229,6 +247,8 @@ void main() {
       expect(repo.state, GitRepositoryState.none);
 
       rebase.free();
+      ontoHead.free();
+      branchHead.free();
       conflict.free();
       master.free();
     });