diff --git a/shared/FlowDef.hpp b/shared/FlowDef.hpp
index 4af016c..ffd7a1f 100644
--- a/shared/FlowDef.hpp
+++ b/shared/FlowDef.hpp
@@ -65,6 +65,9 @@ inline std::string make_audio_flow_def(
         {"sample_rate", {{"numerator", sample_rate},    {"denominator", 1}}},
         {"channels",    ch_arr},
         {"bit_depth",   bit_depth},
+        {"tags", {
+            {"urn:x-nmos:tag:grouphint/v1.0", json::array({label + ":Audio"})}
+        }},
     }.dump();
 }