diff --git a/openflow_input/bsn_tlv b/openflow_input/bsn_tlv
index 1d452ae..16637cd 100644
--- a/openflow_input/bsn_tlv
+++ b/openflow_input/bsn_tlv
@@ -392,5 +392,5 @@
 struct of_bsn_tlv_interval : of_bsn_tlv {
     uint16_t type == 58;
     uint16_t length;
-    uint32_t value;
+    uint32_t value; /* Milliseconds */
 };