diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index f065cdad87..cf765fc560 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -1391,6 +1391,10 @@ static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
         int block_idx    = mb_y * s->block_stride[c];
         int16_t (*block)[64] = &s->blocks[c][block_idx];
         uint8_t *last_nnz    = &s->last_nnz[c][block_idx];
+        if (get_bits_left(&s->gb) <= 0) {
+            av_log(s->avctx, AV_LOG_ERROR, "bitstream truncated in mjpeg_decode_scan_progressive_ac\n");
+            return AVERROR_INVALIDDATA;
+        }
         for (mb_x = 0; mb_x < s->mb_width; mb_x++, block++, last_nnz++) {
                 int ret;
                 if (s->restart_interval && !s->restart_count)