diff --git a/hardware/src/main/kotlin/dev/nextftc/hardware/RobotController.kt b/hardware/src/main/kotlin/dev/nextftc/hardware/RobotController.kt
index aee2f48d..b1900965 100644
--- a/hardware/src/main/kotlin/dev/nextftc/hardware/RobotController.kt
+++ b/hardware/src/main/kotlin/dev/nextftc/hardware/RobotController.kt
@@ -40,6 +40,10 @@ object RobotController : OnCreateEventLoop, OpModeManagerNotifier.Notifications
     hardwareObjects += hardware
   }
 
+  private fun resetHardware() {
+    synchronized(hardwareObjects) { hardwareObjects.toList() }.forEach { it.reset() }
+  }
+
   /**
    * Application context captured when the event loop is created.
    *
@@ -145,7 +149,9 @@ object RobotController : OnCreateEventLoop, OpModeManagerNotifier.Notifications
     ftcEventLoop.opModeManager.registerListener(this)
   }
 
-  override fun onOpModePreInit(opMode: OpMode?) {}
+  override fun onOpModePreInit(opMode: OpMode?) {
+    resetHardware()
+  }
 
   override fun onOpModePreStart(opMode: OpMode?) {}
 
@@ -153,6 +159,6 @@ object RobotController : OnCreateEventLoop, OpModeManagerNotifier.Notifications
    * Discards all cached hardware objects so they are re-initialized in the next op mode.
    */
   override fun onOpModePostStop(opMode: OpMode?) {
-    synchronized(hardwareObjects) { hardwareObjects.toList() }.forEach { it.reset() }
+    resetHardware()
   }
 }
diff --git a/hardware/src/main/kotlin/dev/nextftc/hardware/lynx/NextLynxModule.kt b/hardware/src/main/kotlin/dev/nextftc/hardware/lynx/NextLynxModule.kt
index 5f7c344e..733a253c 100644
--- a/hardware/src/main/kotlin/dev/nextftc/hardware/lynx/NextLynxModule.kt
+++ b/hardware/src/main/kotlin/dev/nextftc/hardware/lynx/NextLynxModule.kt
@@ -52,13 +52,19 @@ class NextLynxModule internal constructor(initializer: () -> LynxModule, @JvmFie
   }
 
   /** Tracks used ports. Resets each OpMode. */
-  private val usedPorts by LazyHardware { HashSet<Pair<PortKind, Int>>() }
+  private val usedPorts by LazyHardware { HashMap<Pair<PortKind, Int>, Throwable>() }
 
   /** Throws if this port is already used on this hub. */
   private fun claim(kind: PortKind, port: Int) {
-    check(usedPorts.add(kind to port)) {
-      "Port conflict on $type: ${kind.name.lowercase()} port $port is used by more than one device"
+    val key = kind to port
+    val first = usedPorts[key]
+    if (first != null) {
+      throw IllegalStateException(
+        "Port conflict on $type: ${kind.name.lowercase()} port $port is used by more than one device",
+        first,
+      )
     }
+    usedPorts[key] = Throwable("Port first claimed here")
   }
 
   /** Current module temperature. */