diff --git a/device/device.cpp b/device/device.cpp
index 3f578fa..9ad6888 100644
--- a/device/device.cpp
+++ b/device/device.cpp
@@ -1878,7 +1878,7 @@ bool Device::subscribeLiveData(std::shared_ptr<LiveDataCommandMessage> message)
 
 	if(response) {
 		auto statusMsg = std::dynamic_pointer_cast<LiveDataStatusMessage>(response);
-		if(statusMsg->requestedCommand == message->cmd) {
+		if(statusMsg && statusMsg->requestedCommand == message->cmd) {
 			switch(statusMsg->status) {
 				case LiveDataStatus::SUCCESS:
 					return true;
diff --git a/platform/posix/firmio.cpp b/platform/posix/firmio.cpp
index 0f62ee3..e432fa6 100644
--- a/platform/posix/firmio.cpp
+++ b/platform/posix/firmio.cpp
@@ -42,9 +42,13 @@ void FirmIO::Find(std::vector<FoundDevice>& found) {
 	Decoder decoder([](APIEvent::Type, APIEvent::Severity) {});
 	using namespace std::chrono;
 	const auto start = steady_clock::now();
-	auto timeout = milliseconds(50);
-	while(temp.readWait(payload, timeout)) {
-		timeout -= duration_cast<milliseconds>(steady_clock::now() - start);
+	// Get an absolute wall clock to compare to
+	const auto overallTimeout = start + milliseconds(500);
+	while(temp.readWait(payload, milliseconds(50))) {
+		if(steady_clock::now() > overallTimeout) {
+			// failed to read out a serial number reponse in time
+			break;
+		}
 
 		if(!packetizer.input(payload))
 			continue; // A full packet has not yet been read out