diff --git a/src/protocols/rdp/channels/rdpsnd/rdpsnd-messages.c b/src/protocols/rdp/channels/rdpsnd/rdpsnd-messages.c
index c057cd11..deec8866 100644
--- a/src/protocols/rdp/channels/rdpsnd/rdpsnd-messages.c
+++ b/src/protocols/rdp/channels/rdpsnd/rdpsnd-messages.c
@@ -296,7 +296,7 @@ void guac_rdpsnd_wave_info_handler(guac_rdp_common_svc* svc,
     rdpsnd->next_pdu_is_wave = TRUE;
 
     /* Reset audio stream if format has changed */
-    if (audio != NULL)
+    if (audio != NULL && format < sizeof(rdpsnd->formats))
         guac_audio_stream_reset(audio, NULL,
                 rdpsnd->formats[format].rate,
                 rdpsnd->formats[format].channels,