diff --git a/libavcodec/tta.c b/libavcodec/tta.c
index 6697d8490539063a27293a5832face76307bf005..b5ddec4f47d5810820e9a80cf6893037cf542e57 100644
--- a/libavcodec/tta.c
+++ b/libavcodec/tta.c
@@ -160,7 +160,7 @@ static av_cold int tta_decode_init(AVCodecContext * avctx)
         return AVERROR_INVALIDDATA;
 
     s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
-    init_get_bits(&gb, avctx->extradata, avctx->extradata_size * 8);
+    init_get_bits8(&gb, avctx->extradata, avctx->extradata_size);
     if (show_bits_long(&gb, 32) == AV_RL32("TTA1")) {
         /* signature */
         skip_bits_long(&gb, 32);