diff --git a/tests/functional/pyocf/rio.py b/tests/functional/pyocf/rio.py
index 09ef495..f11cba9 100644
--- a/tests/functional/pyocf/rio.py
+++ b/tests/functional/pyocf/rio.py
@@ -79,9 +79,10 @@ class JobSpec:
 
 class Rio:
     class RioThread(Thread):
-        def __init__(self, jobspec: JobSpec):
+        def __init__(self, jobspec: JobSpec, queue):
             super().__init__()
             self.jobspec = jobspec
+            self.queue = queue
             self.ios = Size(0)
             self.io_target = 0
             self.finish_time = None
@@ -153,7 +154,7 @@ class Rio:
 
                 data = Data(self.jobspec.bs)  # TODO pattern and verify
                 io = self.jobspec.target.new_io(
-                    self.jobspec.target.cache.get_default_queue(),  # TODO multiple queues?
+                    self.queue,
                     next(iogen),
                     self.jobspec.bs,
                     iodir,
@@ -260,12 +261,12 @@ class Rio:
         self._threads = []
         self.errors = {}
 
-    def run(self):
-        self.run_async()
+    def run(self, queues=None):
+        self.run_async(queues)
         self.wait_for_completion()
         return self
 
-    def run_async(self):
+    def run_async(self, queues=None):
         self.clear()
 
         jobs = deepcopy(self.jobs)
@@ -273,9 +274,13 @@ class Rio:
         if not jobs:
             jobs = [self.global_jobspec for _ in range(self.global_jobspec.njobs)]
 
+        if not queues:
+            queues = [self.global_jobspec.target.cache.get_default_queue()]
+        queues = cycle(queues)
+
         for job in jobs:
             spec = job.merge(self.global_jobspec)
-            thread = Rio.RioThread(spec)
+            thread = Rio.RioThread(spec, next(queues))
             self._threads.append(thread)
 
         for thread in self._threads: