diff --git a/src/ControllerDevice.cpp b/src/ControllerDevice.cpp
index 8fd9147..1d12c4c 100644
--- a/src/ControllerDevice.cpp
+++ b/src/ControllerDevice.cpp
@@ -136,6 +136,9 @@ vr::EVRInitError SlimeVRDriver::ControllerDevice::Activate(uint32_t unObjectId)
 
 void SlimeVRDriver::ControllerDevice::PositionMessage(messages::Position &position)
 {
+    if (this->device_index_ == vr::k_unTrackedDeviceIndexInvalid)
+        return;
+
     // Setup pose for this frame
     auto pose = this->last_pose_;
     //send the new position and rotation from the pipe to the tracker object
diff --git a/src/HMDDevice.cpp b/src/HMDDevice.cpp
index 67a5245..a0e76c3 100644
--- a/src/HMDDevice.cpp
+++ b/src/HMDDevice.cpp
@@ -19,6 +19,9 @@ void SlimeVRDriver::HMDDevice::Update()
 
 void SlimeVRDriver::HMDDevice::PositionMessage(messages::Position &position)
 {
+    if (this->device_index_ == vr::k_unTrackedDeviceIndexInvalid)
+        return;
+
     // Setup pose for this frame
     auto pose = this->last_pose_;
     //send the new position and rotation from the pipe to the tracker object
diff --git a/src/TrackerDevice.cpp b/src/TrackerDevice.cpp
index 9ad99da..d1e7f4a 100644
--- a/src/TrackerDevice.cpp
+++ b/src/TrackerDevice.cpp
@@ -44,6 +44,9 @@ void SlimeVRDriver::TrackerDevice::Update()
 
 void SlimeVRDriver::TrackerDevice::PositionMessage(messages::Position &position)
 {
+    if (this->device_index_ == vr::k_unTrackedDeviceIndexInvalid)
+        return;
+
     // Setup pose for this frame
     auto pose = this->last_pose_;
     //send the new position and rotation from the pipe to the tracker object
diff --git a/src/TrackingReferenceDevice.cpp b/src/TrackingReferenceDevice.cpp
index 672cec2..90a5add 100644
--- a/src/TrackingReferenceDevice.cpp
+++ b/src/TrackingReferenceDevice.cpp
@@ -88,6 +88,9 @@ vr::DriverPose_t SlimeVRDriver::TrackingReferenceDevice::GetPose()
 
 void SlimeVRDriver::TrackingReferenceDevice::PositionMessage(messages::Position &position)
 {
+    if (this->device_index_ == vr::k_unTrackedDeviceIndexInvalid)
+        return;
+
     // Setup pose for this frame
     auto pose = this->last_pose_;
     //send the new position and rotation from the pipe to the tracker object