diff --git a/include/patty/ax25/sock.h b/include/patty/ax25/sock.h
index 13351c0..129e866 100644
--- a/include/patty/ax25/sock.h
+++ b/include/patty/ax25/sock.h
@@ -202,8 +202,6 @@ void patty_ax25_sock_vr_incr(patty_ax25_sock *sock);
 
 int patty_ax25_sock_flow_left(patty_ax25_sock *sock);
 
-int patty_ax25_sock_flow_full(patty_ax25_sock *sock);
-
 /*
  * Frame segment reassembly state machine
  */
diff --git a/src/sock.c b/src/sock.c
index 6661ebf..e32d152 100644
--- a/src/sock.c
+++ b/src/sock.c
@@ -536,14 +536,6 @@ void *patty_ax25_sock_assembler_read(patty_ax25_sock *sock,
 }
 
 int patty_ax25_sock_flow_left(patty_ax25_sock *sock) {
-    if (sock->n_window_tx == 1) {
-        return 1;
-    }
-
-    return sock->vs - tx_seq(sock, sock->va + sock->n_window_tx);
-}
-
-int patty_ax25_sock_flow_full(patty_ax25_sock *sock) {
     /*
      * 6.4.1 Sending I Frames
      *
@@ -552,7 +544,11 @@ int patty_ax25_sock_flow_full(patty_ax25_sock *sock) {
      * k.  If the TNC sent more I frames, the flow control window would be
      * exceeded and errors could result.
      */
-    return sock->vs == tx_seq(sock, sock->va + sock->n_window_tx)? 1: 0;
+    if (sock->n_window_tx == 1) {
+        return 1;
+    }
+
+    return sock->vs - tx_seq(sock, sock->va + sock->n_window_tx);
 }
 
 static inline int toobig(patty_ax25_sock *sock,