diff --git a/libavcodec/webvttdec.c b/libavcodec/webvttdec.c
index 5968359edd..4eabb0de48 100644
--- a/libavcodec/webvttdec.c
+++ b/libavcodec/webvttdec.c
@@ -28,6 +28,7 @@
 #include "avcodec.h"
 #include "ass.h"
 #include "codec_internal.h"
+#include "decode.h"
 #include "libavutil/bprint.h"
 #include "libavutil/mathematics.h"
 
@@ -184,7 +185,7 @@ static int webvtt_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,
                                int *got_sub_ptr, const AVPacket *avpkt)
 {
     int ret = 0;
-    const char *ptr = avpkt->data;
+    const char *ptr = ff_decode_subtitle_text(avctx, avpkt);
     FFASSDecoderContext *s = avctx->priv_data;
     AVBPrint buf;
     AVRational ms = { 1, 1000 };
@@ -199,6 +200,9 @@ static int webvtt_decode_frame(AVCodecContext *avctx, AVSubtitle *sub,
         end_ms   = start_ms + av_rescale_q(avpkt->duration, avctx->pkt_timebase, ms);
     }
 
+    if (avpkt->size > 0 && !ptr)
+        return AVERROR(ENOMEM);
+
     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
     if (ptr && avpkt->size > 0 &&
         !webvtt_event_to_ass(&buf, ptr, start_ms, end_ms))