diff --git a/src/mpd_client.c b/src/mpd_client.c
index 30a56f0..ab09fea 100644
--- a/src/mpd_client.c
+++ b/src/mpd_client.c
@@ -412,7 +412,7 @@ static int mpd_notify_callback(struct mg_connection *c, enum mg_event ev) {
             mpd.buf_size = mpd_put_channels(mpd.buf);
             mg_websocket_write(c, 1, mpd.buf, mpd.buf_size);
         } else {
-            fprintf(stdout, "notify_callback: %i, %s\n", mpd.buf_size, mpd.buf);
+            fprintf(stdout, "notify_callback: %li, %s\n", mpd.buf_size, mpd.buf);
             mg_websocket_write(c, 1, mpd.buf, mpd.buf_size);
         }