diff --git a/libs/openzap/src/testtones.c b/libs/openzap/src/testtones.c
index 2097f26df5..273b793acf 100644
--- a/libs/openzap/src/testtones.c
+++ b/libs/openzap/src/testtones.c
@@ -8,9 +8,13 @@ static int teletone_handler(teletone_generation_session_t *ts, teletone_tone_map
 {
 	struct ttmp *tmp = ts->user_data;
 	int wrote;
+	size_t len;
 
 	wrote = teletone_mux_tones(ts, map);
-	write(tmp->fd, ts->buffer, wrote * 2);
+	len = write(tmp->fd, ts->buffer, wrote * 2);
+	
+	if (!len) return -1;
+
 	return 0;
 }
 
@@ -49,6 +53,7 @@ int32_t main(int argc, char *argv[])
 	int32_t durations[] = {274, 274, 380, 0};
 	teletone_dds_state_t dds = {0};
 	int16_t sample;
+	size_t len = 1;
 
 	if (argc < 2 || (fd = open(argv[1], O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR)) < 0) {
 		fprintf(stderr, "File Error!\n", strerror(errno));
@@ -59,9 +64,9 @@ int32_t main(int argc, char *argv[])
 
 		teletone_dds_state_set_tone(&dds, tones[j], rate, -50);
 		
-		for(i = 0; i < durations[j] * rate / 1000; i++) {
+		for(i = 0; (i < durations[j] * rate / 1000) && len != 0; i++) {
 			sample = teletone_dds_modulate_sample(&dds) * 20;
-			write(fd, &sample, sizeof(sample));
+			len = write(fd, &sample, sizeof(sample));
 		}
 
 	}