diff --git a/lib/workers/repository/onboarding/branch/rebase.js b/lib/workers/repository/onboarding/branch/rebase.js
index a67542de64f9d4918535f381f9831598078b59b3..4e1ed81b52d0c433bd9a2ffc3e3aecd8fe6ed003 100644
--- a/lib/workers/repository/onboarding/branch/rebase.js
+++ b/lib/workers/repository/onboarding/branch/rebase.js
@@ -6,6 +6,22 @@ const {
 
 const defaultConfigFile = configFileNames[0];
 
+function getCommitMessage(config) {
+  let commitMessage;
+  // istanbul ignore if
+  if (config.semanticCommits) {
+    commitMessage = config.semanticCommitType;
+    if (config.semanticCommitScope) {
+      commitMessage += `(${config.semanticCommitScope})`;
+    }
+    commitMessage += ': ';
+    commitMessage += 'add ' + defaultConfigFile;
+  } else {
+    commitMessage = 'Add ' + defaultConfigFile;
+  }
+  return commitMessage;
+}
+
 async function rebaseOnboardingBranch(config) {
   logger.debug('Checking if onboarding branch needs rebasing');
   const pr = await platform.getBranchPr(onboardingBranch);
@@ -23,18 +39,9 @@ async function rebaseOnboardingBranch(config) {
     return;
   }
   logger.info('Rebasing onboarding branch');
-  let commitMessage;
-  // istanbul ignore if
-  if (config.semanticCommits) {
-    commitMessage = config.semanticCommitType;
-    if (config.semanticCommitScope) {
-      commitMessage += `(${config.semanticCommitScope})`;
-    }
-    commitMessage += ': ';
-    commitMessage += 'add ' + defaultConfigFile;
-  } else {
-    commitMessage = 'Add ' + defaultConfigFile;
-  }
+  // istanbul ignore next
+  const commitMessage = getCommitMessage(config);
+
   // istanbul ignore if
   if (config.dryRun) {
     logger.info('DRY-RUN: Would rebase files in onboarding branch');