diff --git a/scripts/simplebench/bench-example.py b/scripts/simplebench/bench-example.py
index d9c7f7bc17e71b5838d418b67fed8f14afb8d263..4864435f396f9b7e49cad2c38bf4119ad6d1af20 100644
--- a/scripts/simplebench/bench-example.py
+++ b/scripts/simplebench/bench-example.py
@@ -25,7 +25,7 @@
 
 def bench_func(env, case):
     """ Handle one "cell" of benchmarking table. """
-    return bench_block_copy(env['qemu_binary'], env['cmd'],
+    return bench_block_copy(env['qemu_binary'], env['cmd'], {}
                             case['source'], case['target'])
 
 
diff --git a/scripts/simplebench/bench_block_job.py b/scripts/simplebench/bench_block_job.py
index a0dda1dc4e61a789543aab850dac3df34bb0d30f..7332845c1c9a3b15487fa4b40c7bd3cc19a4ed59 100755
--- a/scripts/simplebench/bench_block_job.py
+++ b/scripts/simplebench/bench_block_job.py
@@ -78,16 +78,19 @@ def bench_block_job(cmd, cmd_args, qemu_args):
 
 
 # Bench backup or mirror
-def bench_block_copy(qemu_binary, cmd, source, target):
+def bench_block_copy(qemu_binary, cmd, cmd_options, source, target):
     """Helper to run bench_block_job() for mirror or backup"""
     assert cmd in ('blockdev-backup', 'blockdev-mirror')
 
     source['node-name'] = 'source'
     target['node-name'] = 'target'
 
-    return bench_block_job(cmd,
-                           {'job-id': 'job0', 'device': 'source',
-                            'target': 'target', 'sync': 'full'},
+    cmd_options['job-id'] = 'job0'
+    cmd_options['device'] = 'source'
+    cmd_options['target'] = 'target'
+    cmd_options['sync'] = 'full'
+
+    return bench_block_job(cmd, cmd_options,
                            [qemu_binary,
                             '-blockdev', json.dumps(source),
                             '-blockdev', json.dumps(target)])