diff --git a/libavcodec/svq1dec.c b/libavcodec/svq1dec.c
index 7fef10bb99..7c4e5c960c 100644
--- a/libavcodec/svq1dec.c
+++ b/libavcodec/svq1dec.c
@@ -676,6 +676,7 @@ static int svq1_decode_frame(AVCodecContext *avctx,
 #endif
     return result;
   }
+  avcodec_set_dimensions(avctx, s->width, s->height);
 
   //FIXME this avoids some confusion for "B frames" without 2 references
   //this should be removed after libavcodec can handle more flexible picture types & ordering