diff --git a/include/haproxy/mux_quic-t.h b/include/haproxy/mux_quic-t.h
index 4ca53688f..97a6dd765 100644
--- a/include/haproxy/mux_quic-t.h
+++ b/include/haproxy/mux_quic-t.h
@@ -175,6 +175,8 @@ enum qcs_tx_st {
 #define QC_SF_WANT_SHUTW        0x00010000  // a stream couldn't shutw() (mux full/busy)
 #define QC_SF_KILL_CONN         0x00020000  // kill the whole connection with this stream
 
+#define QC_SF_FIN_STREAM        0x00040000  // FIN bit must be set for last frame of the stream
+
 /* QUIC stream descriptor, describing the stream as it appears in the QUIC_CONN, and as
  * it is being processed in the internal HTTP representation (HTX).
  */