diff --git a/p2p/enr/enr.go b/p2p/enr/enr.go
index d2ee5b4bd2..2d155450e6 100644
--- a/p2p/enr/enr.go
+++ b/p2p/enr/enr.go
@@ -34,6 +34,8 @@ import (
 )
 
 const (
+	// SizeLimit is the maximum encoded size of a node record in bytes.
+	// Implementations should reject records larger than this size.
 	SizeLimit = 300
 )