diff --git a/src/stats/tb/taxi_stats_collect/test_taxi_stats_collect.py b/src/stats/tb/taxi_stats_collect/test_taxi_stats_collect.py
index 0144d67..1d83f8c 100644
--- a/src/stats/tb/taxi_stats_collect/test_taxi_stats_collect.py
+++ b/src/stats/tb/taxi_stats_collect/test_taxi_stats_collect.py
@@ -20,7 +20,6 @@ import cocotb
 from cocotb.clock import Clock
 from cocotb.queue import Queue
 from cocotb.triggers import RisingEdge, Timer
-from cocotb.regression import TestFactory
 
 from cocotbext.axi import AxiStreamBus, AxiStreamSink
 
@@ -64,6 +63,14 @@ class TB(object):
         await RisingEdge(self.dut.clk)
 
 
+def cycle_pause():
+    return itertools.cycle([1, 1, 1, 0])
+
+
+@cocotb.test()
+@cocotb.parametrize(
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_test_acc(dut, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -105,6 +112,10 @@ async def run_test_acc(dut, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
+@cocotb.test()
+@cocotb.parametrize(
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_test_max(dut, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -144,6 +155,10 @@ async def run_test_max(dut, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
+@cocotb.test()
+@cocotb.parametrize(
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_test_str(dut, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -192,6 +207,10 @@ async def run_test_str(dut, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
+@cocotb.test()
+@cocotb.parametrize(
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_stress_test(dut, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -271,24 +290,6 @@ async def run_stress_test(dut, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
-def cycle_pause():
-    return itertools.cycle([1, 1, 1, 0])
-
-
-if getattr(cocotb, 'top', None) is not None:
-
-    for test in [
-                run_test_acc,
-                run_test_max,
-                run_test_str,
-                run_stress_test,
-            ]:
-
-        factory = TestFactory(test)
-        factory.add_option("backpressure_inserter", [None, cycle_pause])
-        factory.generate_tests()
-
-
 # cocotb-test
 
 tests_dir = os.path.dirname(__file__)
diff --git a/src/stats/tb/taxi_stats_counter/test_taxi_stats_counter.py b/src/stats/tb/taxi_stats_counter/test_taxi_stats_counter.py
index 4f98a52..d81c01f 100644
--- a/src/stats/tb/taxi_stats_counter/test_taxi_stats_counter.py
+++ b/src/stats/tb/taxi_stats_counter/test_taxi_stats_counter.py
@@ -21,7 +21,6 @@ import cocotb
 from cocotb.clock import Clock
 from cocotb.queue import Queue
 from cocotb.triggers import RisingEdge, Timer
-from cocotb.regression import TestFactory
 
 from cocotbext.axi import AxiLiteBus, AxiLiteMaster
 from cocotbext.axi import AxiStreamBus, AxiStreamSource, AxiStreamFrame
@@ -64,6 +63,15 @@ class TB(object):
         await RisingEdge(self.dut.clk)
 
 
+def cycle_pause():
+    return itertools.cycle([1, 1, 1, 0])
+
+
+@cocotb.test()
+@cocotb.parametrize(
+    ("idle_inserter", [None, cycle_pause]),
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_test_acc(dut, idle_inserter=None, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -95,6 +103,11 @@ async def run_test_acc(dut, idle_inserter=None, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
+@cocotb.test()
+@cocotb.parametrize(
+    ("idle_inserter", [None, cycle_pause]),
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_stress_test(dut, idle_inserter=None, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -151,23 +164,6 @@ async def run_stress_test(dut, idle_inserter=None, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
-def cycle_pause():
-    return itertools.cycle([1, 1, 1, 0])
-
-
-if getattr(cocotb, 'top', None) is not None:
-
-    for test in [run_test_acc]:
-
-        factory = TestFactory(test)
-        factory.add_option("idle_inserter", [None, cycle_pause])
-        factory.add_option("backpressure_inserter", [None, cycle_pause])
-        factory.generate_tests()
-
-    factory = TestFactory(run_stress_test)
-    factory.generate_tests()
-
-
 # cocotb-test
 
 tests_dir = os.path.dirname(__file__)
diff --git a/src/stats/tb/taxi_stats_strings_full/test_taxi_stats_strings_full.py b/src/stats/tb/taxi_stats_strings_full/test_taxi_stats_strings_full.py
index 2f422c4..c4e3d26 100644
--- a/src/stats/tb/taxi_stats_strings_full/test_taxi_stats_strings_full.py
+++ b/src/stats/tb/taxi_stats_strings_full/test_taxi_stats_strings_full.py
@@ -18,7 +18,6 @@ import cocotb_test.simulator
 import cocotb
 from cocotb.clock import Clock
 from cocotb.triggers import RisingEdge, Timer
-from cocotb.regression import TestFactory
 
 from cocotbext.axi import AxiLiteBus, AxiLiteMaster
 from cocotbext.axi import AxiStreamBus, AxiStreamSource, AxiStreamFrame
@@ -61,6 +60,15 @@ class TB(object):
         await RisingEdge(self.dut.clk)
 
 
+def cycle_pause():
+    return itertools.cycle([1, 1, 1, 0])
+
+
+@cocotb.test()
+@cocotb.parametrize(
+    ("idle_inserter", [None, cycle_pause]),
+    ("backpressure_inserter", [None, cycle_pause]),
+)
 async def run_test_strings(dut, idle_inserter=None, backpressure_inserter=None):
 
     tb = TB(dut)
@@ -109,20 +117,6 @@ async def run_test_strings(dut, idle_inserter=None, backpressure_inserter=None):
     await RisingEdge(dut.clk)
 
 
-def cycle_pause():
-    return itertools.cycle([1, 1, 1, 0])
-
-
-if getattr(cocotb, 'top', None) is not None:
-
-    for test in [run_test_strings]:
-
-        factory = TestFactory(test)
-        factory.add_option("idle_inserter", [None, cycle_pause])
-        factory.add_option("backpressure_inserter", [None, cycle_pause])
-        factory.generate_tests()
-
-
 # cocotb-test
 
 tests_dir = os.path.dirname(__file__)