diff --git a/lib/util/git/index.spec.ts b/lib/util/git/index.spec.ts
index de9da6eaa15603db410f3911bdfd68b18bee77f4..63cd732cf2d1c50e08b11f9dbec5af3b918b7a74 100644
--- a/lib/util/git/index.spec.ts
+++ b/lib/util/git/index.spec.ts
@@ -225,6 +225,12 @@ describe('util/git/index', () => {
 
   describe('mergeBranch(branchName)', () => {
     it('should perform a branch merge', async () => {
+      const repo = Git(GlobalConfig.get('localDir'));
+      await repo.checkout([
+        '-B',
+        'renovate/future_branch',
+        'origin/renovate/future_branch',
+      ]);
       await git.mergeBranch('renovate/future_branch');
       const merged = await Git(origin.path).branch([
         '--verbose',
diff --git a/lib/util/git/index.ts b/lib/util/git/index.ts
index 2b3df1332622483ad6e52e89ebd8237984b1386c..3358b96e60d01bbee920f983f22dc43c035d5d09 100644
--- a/lib/util/git/index.ts
+++ b/lib/util/git/index.ts
@@ -653,7 +653,6 @@ export async function mergeBranch(branchName: string): Promise<void> {
   try {
     await syncGit();
     await git.reset(ResetMode.HARD);
-    await git.checkout(['-B', branchName, 'origin/' + branchName]);
     await git.checkout([
       '-B',
       config.currentBranch,