diff --git a/profile/plugin/ml_timeline/clientDev/ml_timeline.cpp b/profile/plugin/ml_timeline/clientDev/ml_timeline.cpp
index 58835341..80368bbb 100644
--- a/profile/plugin/ml_timeline/clientDev/ml_timeline.cpp
+++ b/profile/plugin/ml_timeline/clientDev/ml_timeline.cpp
@@ -195,6 +195,7 @@ namespace xdp {
     if (!powerMode.empty()) {
       ptHeader.put("power_mode", powerMode);
     }
+    ptHeader.put("clock_freq_MHz", "");
     ptHeader.put("id_size", sizeof(uint32_t));
     ptHeader.put("cycle_size", 2*sizeof(uint32_t));
     ptHeader.put("buffer_size", mBufSz);