diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
index d4f18b9841..7ed6ce3135 100644
--- a/libavcodec/wmalosslessdec.c
+++ b/libavcodec/wmalosslessdec.c
@@ -1327,6 +1327,7 @@ AVCodec ff_wmalossless_decoder = {
     .decode         = decode_packet,
     .flush          = flush,
     .capabilities   = AV_CODEC_CAP_SUBFRAMES | AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
                                                       AV_SAMPLE_FMT_S32P,
                                                       AV_SAMPLE_FMT_NONE },