diff --git a/src/scheduler.cpp b/src/scheduler.cpp
index 35bf0da4bec..36a6d5110d9 100644
--- a/src/scheduler.cpp
+++ b/src/scheduler.cpp
@@ -140,6 +140,10 @@ size_t CScheduler::getQueueInfo(boost::chrono::system_clock::time_point &first,
     return result;
 }
 
+bool CScheduler::AreThreadsServicingQueue() const {
+    return nThreadsServicingQueue;
+}
+
 
 void SingleThreadedSchedulerClient::MaybeScheduleProcessQueue() {
     {
@@ -193,6 +197,7 @@ void SingleThreadedSchedulerClient::AddToProcessQueue(std::function<void (void)>
 }
 
 void SingleThreadedSchedulerClient::EmptyQueue() {
+    assert(!m_pscheduler->AreThreadsServicingQueue());
     bool should_continue = true;
     while (should_continue) {
         ProcessQueue();
diff --git a/src/scheduler.h b/src/scheduler.h
index 6a079f7749e..0365d668b20 100644
--- a/src/scheduler.h
+++ b/src/scheduler.h
@@ -71,6 +71,9 @@ public:
     size_t getQueueInfo(boost::chrono::system_clock::time_point &first,
                         boost::chrono::system_clock::time_point &last) const;
 
+    // Returns true if there are threads actively running in serviceQueue()
+    bool AreThreadsServicingQueue() const;
+
 private:
     std::multimap<boost::chrono::system_clock::time_point, Function> taskQueue;
     boost::condition_variable newTaskScheduled;
@@ -103,6 +106,7 @@ public:
     void AddToProcessQueue(std::function<void (void)> func);
 
     // Processes all remaining queue members on the calling thread, blocking until queue is empty
+    // Must be called after the CScheduler has no remaining processing threads!
     void EmptyQueue();
 };