diff --git a/apps/ndn-producer.h b/apps/ndn-producer.h
index 8349ea2..1cf21fe 100644
--- a/apps/ndn-producer.h
+++ b/apps/ndn-producer.h
@@ -32,6 +32,7 @@
 namespace ndn {
 
 /**
+ * @ingroup ndn-apps
  * @brief A simple Interest-sink applia simple Interest-sink application
  *
  * A simple Interest-sink applia simple Interest-sink application,