diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 5967fca285..2cf01e3d98 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -47,10 +47,9 @@
 
 static enum AVPixelFormat h263_get_format(AVCodecContext *avctx)
 {
-    MpegEncContext *s = avctx->priv_data;
     /* MPEG-4 Studio Profile only, not supported by hardware */
     if (avctx->bits_per_raw_sample > 8) {
-        av_assert1(s->studio_profile);
+        av_assert1(((MpegEncContext *)avctx->priv_data)->studio_profile);
         return avctx->pix_fmt;
     }