diff --git a/src/kiss.c b/src/kiss.c
index 9825ca7..3dedd43 100644
--- a/src/kiss.c
+++ b/src/kiss.c
@@ -376,6 +376,10 @@ ssize_t patty_kiss_tnc_send(patty_kiss_tnc *tnc,
         goto error_io;
     }
 
+    if (tcdrain(tnc->fd) < 0) {
+        goto error_io;
+    }
+
     return len;
 
 error_io: