diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -3484,7 +3484,7 @@
             printname = name
             if name is None:
                 printname = b'unfiltered'
-            timer(getbranchmap(name), title=str(printname))
+            timer(getbranchmap(name), title=printname)
     finally:
         branchcacheread.restore()
         branchcachewrite.restore()