diff --git a/lib/workers/repository/finalise/prune.ts b/lib/workers/repository/finalise/prune.ts
index 090932ab1e2920b878d974500c81c7176033a6a5..8c89298115db7296d7ecec28f7197da2fcd2814a 100644
--- a/lib/workers/repository/finalise/prune.ts
+++ b/lib/workers/repository/finalise/prune.ts
@@ -52,7 +52,7 @@ async function cleanUpBranches(
           );
           let newPrTitle = pr.title;
           if (!pr.title.endsWith('- autoclosed')) {
-            newPrTitle += '- autoclosed';
+            newPrTitle += ' - autoclosed';
           }
           await platform.updatePr({
             number: pr.number,