diff --git a/internal/proxy/type_def.go b/internal/proxy/type_def.go
index 3f08bbf308..cee5b5adbd 100644
--- a/internal/proxy/type_def.go
+++ b/internal/proxy/type_def.go
@@ -18,6 +18,8 @@ package proxy
 
 // vChan shortcuts for virtual channel.
 type vChan = string
+
+// pChan shortcuts for physical channel.
 type pChan = string
 
 type pChanStatistics struct {