diff --git a/samplesource.cpp b/samplesource.cpp
index cb7a23f..ba53221 100644
--- a/samplesource.cpp
+++ b/samplesource.cpp
@@ -39,6 +39,12 @@ void SampleSource<T>::invalidate()
 	}
 }
 
+template<typename T>
+int SampleSource<T>::subscriberCount()
+{
+	return subscribers.size();
+}
+
 template<typename T>
 void SampleSource<T>::unsubscribe(Subscriber *subscriber)
 {
diff --git a/samplesource.h b/samplesource.h
index 7cd5834..14243ef 100644
--- a/samplesource.h
+++ b/samplesource.h
@@ -38,6 +38,7 @@ public:
     virtual off_t rate() = 0;
     std::type_index sampleType() override;
     void subscribe(Subscriber *subscriber);
+    int subscriberCount();
     void unsubscribe(Subscriber *subscriber);
 
 protected: