diff --git a/api/data_channel_interface.h b/api/data_channel_interface.h
index 5b2b126..56bb6c9 100644
--- a/api/data_channel_interface.h
+++ b/api/data_channel_interface.h
@@ -44,11 +44,13 @@
   //
   // Cannot be set along with |maxRetransmits|.
   // This is called |maxPacketLifeTime| in the WebRTC JS API.
+  // Negative values are ignored, and positive values are clamped to [0-65535]
   absl::optional<int> maxRetransmitTime;
 
   // The max number of retransmissions.
   //
   // Cannot be set along with |maxRetransmitTime|.
+  // Negative values are ignored, and positive values are clamped to [0-65535]
   absl::optional<int> maxRetransmits;
 
   // This is set by the application and opaque to the WebRTC implementation.