diff --git a/admin.proto b/admin.proto
index c5bdc4b..7b9d653 100644
--- a/admin.proto
+++ b/admin.proto
@@ -40,6 +40,7 @@ message AdminMessage {
   
        /*
         * Send the specified channel in the response for this message
+        * NOTE: This field is sent with the channel index + 1 (to ensure we never try to send 'zero' - which protobufs treats as not present)
         */
         uint32 get_channel_request = 6;
         Channel get_channel_response = 7;
diff --git a/docs/docs.md b/docs/docs.md
index 4b74b7d..8230021 100644
--- a/docs/docs.md
+++ b/docs/docs.md
@@ -82,7 +82,7 @@ FIXME - move the radioconfig/user/channel READ operations into AdminMessage as w
 | set_channel | [Channel](#Channel) |  | Set channels (using the new API). A special channel is the "primary channel". The other records are secondary channels. Note: only one channel can be marked as primary. If the client sets a particular channel to be primary, the previous channel will be set to SECONDARY automatically |
 | get_radio_request | [bool](#bool) |  | Send the current RadioConfig in the response for this message |
 | get_radio_response | [RadioConfig](#RadioConfig) |  |  |
-| get_channel_request | [uint32](#uint32) |  | Send the specified channel in the response for this message |
+| get_channel_request | [uint32](#uint32) |  | Send the specified channel in the response for this message NOTE: This field is sent with the channel index + 1 (to ensure we never try to send 'zero' - which protobufs treats as not present) |
 | get_channel_response | [Channel](#Channel) |  |  |