diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 40c24f8adb..8665cac1c0 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1703,7 +1703,7 @@ static int decode_frame(AVCodecContext *avctx, void *data,
     if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)
         return ret;
 
-    if (bytestream2_get_bytes_left(&s->gb) < nb_blocks * 8)
+    if (bytestream2_get_bytes_left(&s->gb)/8 < nb_blocks)
         return AVERROR_INVALIDDATA;
 
     // save pointer we are going to use in decode_block