diff --git a/tb/pcs.py b/tb/pcs.py
index c73993a..2a7a846 100644
--- a/tb/pcs.py
+++ b/tb/pcs.py
@@ -268,6 +268,4 @@ async def test_rx(pcs, valids):
     for _ in range(10):
         assert [0x5, 0x5] == await alist(mii_recv_packet(pcs))
 
-rx_tests = TestFactory(test_rx)
-rx_tests.add_option('valids', (one_valid, two_valid, rand_valid, saw_valid()))
-rx_tests.generate_tests()
+with_valids(globals(), test_rx)
diff --git a/tb/util.py b/tb/util.py
index ed8c12f..537d708 100644
--- a/tb/util.py
+++ b/tb/util.py
@@ -89,6 +89,15 @@ class saw_valid:
             self.last = 0
         return self.last
 
+def with_valids(g, f):
+    for valids in (one_valid, two_valid, rand_valid, saw_valid()):
+        async def test(*args, valids=valids, **kwargs):
+            await f(*args, valids=valids, **kwargs)
+        test.__name__ = f"{f.__name__}_{valids.__qualname__}"
+        test.__qualname__ = f"{f.__qualname__}_{valids.__qualname__}"
+        test.valids = valids
+        g[test.__name__] = cocotb.test()(test)
+
 async def send_recovered_bits(clk, data, valid, bits, valids):
     bits = iter(bits)
     await FallingEdge(clk)