diff --git a/libavcodec/dnxhddec.c b/libavcodec/dnxhddec.c
index cb1fc798b2..862e964b51 100644
--- a/libavcodec/dnxhddec.c
+++ b/libavcodec/dnxhddec.c
@@ -273,14 +273,18 @@ static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,
     if (header_prefix == DNXHD_HEADER_HR2) {
         ctx->data_offset = 0x170 + (ctx->mb_height << 2);
     } else {
-        if (ctx->mb_height > 68 ||
-            (ctx->mb_height << frame->interlaced_frame) > (ctx->height + 15) >> 4) {
+        if (ctx->mb_height > 68) {
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "mb height too big: %d\n", ctx->mb_height);
             return AVERROR_INVALIDDATA;
         }
         ctx->data_offset = 0x280;
     }
+    if ((ctx->mb_height << frame->interlaced_frame) > (ctx->height + 15) >> 4) {
+        av_log(ctx->avctx, AV_LOG_ERROR,
+                "mb height too big: %d\n", ctx->mb_height);
+        return AVERROR_INVALIDDATA;
+    }
 
     if (buf_size < ctx->data_offset) {
         av_log(ctx->avctx, AV_LOG_ERROR,