diff --git a/internal/common/common.go b/internal/common/common.go
index 4bde86baf0..6af93694e8 100644
--- a/internal/common/common.go
+++ b/internal/common/common.go
@@ -51,5 +51,6 @@ const (
 	InvalidFieldID = int64(-1)
 )
 
-// Common implementation of ByteOrder for whole milvus
+// Endian is type alias of binary.LittleEndian.
+// Milvus uses little endian by default.
 var Endian = binary.LittleEndian