diff --git a/tools/bench-asyncio-write.py b/tools/bench-asyncio-write.py
index 5ae347172fb..3c35f295a58 100644
--- a/tools/bench-asyncio-write.py
+++ b/tools/bench-asyncio-write.py
@@ -123,10 +123,11 @@ async def bench(job_title, w, body, base=None):
         base = await bench(t, writes[0], c)
         for w in writes[1:]:
             await bench("", w, c, base)
-    with open("bench.md", "w") as f:
-        for line in res:
-            f.write("| {} |\n".format(" | ".join(line)))
+    return res
 
 
 loop = asyncio.get_event_loop()
-loop.run_until_complete(main(loop))
+results = loop.run_until_complete(main(loop))
+with open("bench.md", "w") as f:
+    for line in results:
+        f.write("| {} |\n".format(" | ".join(line)))