diff --git a/src/sock.c b/src/sock.c
index dc6f3a6..869885b 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -454,12 +454,12 @@ static uint16_t control_i(patty_ax25_sock *sock, int flag) {
     switch (sock->mode) {
         case PATTY_AX25_SOCK_SABM:
             return ((sock->seq_recv & 0x07) << 5)
-                 | ((sock->seq_send & 0x07))
+                 | ((sock->seq_send & 0x07) << 1)
                  | (flag << 4);
 
         case PATTY_AX25_SOCK_SABME:
             return ((sock->seq_recv & 0x7f) << 9)
-                 | ((sock->seq_send & 0x7f))
+                 | ((sock->seq_send & 0x7f) << 1)
                  | (flag << 8);
 
         default: