diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index cc2795e5c5..dd349a4a50 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -973,6 +973,11 @@ static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s,
         return AVERROR_INVALIDDATA;
     }
 
+    if (s->pic_state & PNG_IDAT) {
+        av_log(avctx, AV_LOG_ERROR, "fctl after IDAT\n");
+        return AVERROR_INVALIDDATA;
+    }
+
     s->last_w = s->cur_w;
     s->last_h = s->cur_h;
     s->last_x_offset = s->x_offset;