diff --git a/scripts/perf_bottleneck_finder.py b/scripts/perf_bottleneck_finder.py
index 0ec0f7b..1e2c5b0 100644
--- a/scripts/perf_bottleneck_finder.py
+++ b/scripts/perf_bottleneck_finder.py
@@ -507,8 +507,7 @@ def format_markdown(report: PerfReport) -> str:
                 lines.append(f"- {icon} {b.name}{loc} — ~{b.duration_s:.1f}s — {b.recommendation}")
             lines.append(f"")
 
-    return "
-".join(lines)
+    return "\n".join(lines)
 
 
 # ── Main ───────────────────────────────────────────────────────────