diff --git a/lib/util/git/index.spec.ts b/lib/util/git/index.spec.ts
index bf9445b65f77e5a886f85df12a0262ea5625eeb3..f0115244c4dc319a88731bcf3285e12eb074354a 100644
--- a/lib/util/git/index.spec.ts
+++ b/lib/util/git/index.spec.ts
@@ -77,6 +77,9 @@ describe(getName(), () => {
     });
     await git.setUserRepoConfig({ branchPrefix: 'renovate/' });
     await git.syncGit();
+    // override some local git settings for better testing
+    const local = Git(tmpDir.path);
+    await local.addConfig('commit.gpgsign', 'false');
   });
 
   afterEach(async () => {
diff --git a/lib/util/git/index.ts b/lib/util/git/index.ts
index 01629bd80012e91466653befdaba669eba82bc53..e0c6ea5c83f5cb161d66ba1c6c5f5a465767a2dc 100644
--- a/lib/util/git/index.ts
+++ b/lib/util/git/index.ts
@@ -332,11 +332,11 @@ export async function syncGit(): Promise<void> {
     const { gitAuthorName, gitAuthorEmail } = config;
     if (gitAuthorName) {
       logger.debug({ gitAuthorName }, 'Setting git author name');
-      await git.raw(['config', 'user.name', gitAuthorName]);
+      await git.addConfig('user.name', gitAuthorName);
     }
     if (gitAuthorEmail) {
       logger.debug({ gitAuthorEmail }, 'Setting git author email');
-      await git.raw(['config', 'user.email', gitAuthorEmail]);
+      await git.addConfig('user.email', gitAuthorEmail);
     }
   } catch (err) /* istanbul ignore next */ {
     checkForPlatformFailure(err);