diff --git a/src/event/Loop.cxx b/src/event/Loop.cxx
index 3782ad405..f2b42af6b 100644
--- a/src/event/Loop.cxx
+++ b/src/event/Loop.cxx
@@ -269,8 +269,7 @@ void
 EventLoop::Run() noexcept
 {
 #ifdef HAVE_THREADED_EVENT_LOOP
-	if (thread.IsNull())
-		thread = ThreadId::GetCurrent();
+	assert(!thread.IsNull());
 #endif
 
 	assert(IsInside());
diff --git a/src/event/Loop.hxx b/src/event/Loop.hxx
index a904f15de..5163bcb70 100644
--- a/src/event/Loop.hxx
+++ b/src/event/Loop.hxx
@@ -147,6 +147,12 @@ public:
 	explicit EventLoop(ThreadId _thread);
 
 	EventLoop():EventLoop(ThreadId::GetCurrent()) {}
+
+	void SetThread(ThreadId _thread) noexcept {
+		assert(thread.IsNull());
+
+		thread = _thread;
+	}
 #else
 	EventLoop();
 #endif
diff --git a/src/event/Thread.cxx b/src/event/Thread.cxx
index dc6299a6c..d756171c9 100644
--- a/src/event/Thread.cxx
+++ b/src/event/Thread.cxx
@@ -39,6 +39,8 @@ EventThread::Run() noexcept
 {
 	SetThreadName(realtime ? "rtio" : "io");
 
+	event_loop.SetThread(ThreadId::GetCurrent());
+
 	if (realtime) {
 		SetThreadTimerSlack(std::chrono::microseconds(10));