diff --git a/src/main/scala/uncore/apb/Test.scala b/src/main/scala/uncore/apb/Test.scala
index 198d25b1..80d707a4 100644
--- a/src/main/scala/uncore/apb/Test.scala
+++ b/src/main/scala/uncore/apb/Test.scala
@@ -16,7 +16,7 @@ class RRTest1(address: BigInt)(implicit p: Parameters) extends APBRegisterRouter
   new APBRegBundle((), _)    with RRTest1Bundle)(
   new APBRegModule((), _, _) with RRTest1Module)
 
-class APBFuzzBridge()(implicit p: Parameters) extends LazyModule
+class APBFuzzBridge(aFlow: Boolean)(implicit p: Parameters) extends LazyModule
 {
   val fuzz  = LazyModule(new TLFuzzer(5000))
   val model = LazyModule(new TLRAMModel("APBFuzzMaster"))
@@ -28,7 +28,7 @@ class APBFuzzBridge()(implicit p: Parameters) extends LazyModule
   ram.node  := xbar.node
   gpio.node := xbar.node
   xbar.node :=
-    TLToAPB()(
+    TLToAPB(aFlow)(
     TLDelayer(0.2)(
     TLBuffer(BufferParams.flow)(
     TLDelayer(0.2)(
@@ -39,7 +39,7 @@ class APBFuzzBridge()(implicit p: Parameters) extends LazyModule
   }
 }
 
-class APBBridgeTest()(implicit p: Parameters) extends UnitTest(500000) {
-  val dut = Module(LazyModule(new APBFuzzBridge).module)
+class APBBridgeTest(aFlow: Boolean)(implicit p: Parameters) extends UnitTest(500000) {
+  val dut = Module(LazyModule(new APBFuzzBridge(aFlow)).module)
   io.finished := dut.io.finished
 }
diff --git a/src/main/scala/unittest/Configs.scala b/src/main/scala/unittest/Configs.scala
index 482e72bf..ac825820 100644
--- a/src/main/scala/unittest/Configs.scala
+++ b/src/main/scala/unittest/Configs.scala
@@ -15,7 +15,8 @@ class WithUncoreUnitTests extends Config((site, here, up) => {
       Module(new uncore.ahb.AHBBridgeTest(true)),
       Module(new uncore.ahb.AHBNativeTest(true)),
       Module(new uncore.ahb.AHBNativeTest(false)),
-      Module(new uncore.apb.APBBridgeTest),
+      Module(new uncore.apb.APBBridgeTest(true)),
+      Module(new uncore.apb.APBBridgeTest(false)),
       Module(new uncore.axi4.AXI4LiteFuzzRAMTest),
       Module(new uncore.axi4.AXI4FullFuzzRAMTest),
       Module(new uncore.axi4.AXI4BridgeTest)) }