diff --git a/src/if.c b/src/if.c
index cd6d817..c747c85 100644
--- a/src/if.c
+++ b/src/if.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
+#include <termios.h>
 #include <errno.h>
 
 #include <patty/ax25.h>
@@ -323,7 +324,14 @@ static int handle_promisc_frame(void *key,
     int fd = (int)(value - NULL);
     struct promisc_frame *frame = ctx;
 
-    return write(fd, frame->buf, frame->len);
+    if (write(fd, frame->buf, frame->len) < 0) {
+        goto error_write;
+    }
+
+    return tcdrain(fd);
+
+error_write:
+    return -1;
 }
 
 ssize_t patty_ax25_if_recv(patty_ax25_if *iface,