diff --git a/src/protocol/frame/frame.rs b/src/protocol/frame/frame.rs
index 5992932..e6a0009 100644
--- a/src/protocol/frame/frame.rs
+++ b/src/protocol/frame/frame.rs
@@ -51,7 +51,7 @@ pub struct FrameHeader {
     /// WebSocket protocol opcode.
     pub opcode: OpCode,
     /// A frame mask, if any.
-    mask: Option<[u8; 4]>,
+    pub mask: Option<[u8; 4]>,
 }
 
 impl Default for FrameHeader {