diff --git a/libavcodec/rv34.c b/libavcodec/rv34.c
index ae57973a3adef7c0490449f37ed3ed27ed564e7d..820fb22b211b1885ae1d26285a1ef70ad84aa871 100644
--- a/libavcodec/rv34.c
+++ b/libavcodec/rv34.c
@@ -1402,7 +1402,7 @@ int ff_rv34_decode_frame(AVCodecContext *avctx,
         return -1;
     }
     init_get_bits(&s->gb, buf+get_slice_offset(avctx, slices_hdr, 0), buf_size-get_slice_offset(avctx, slices_hdr, 0));
-    if(r->parse_slice_header(r, &r->s.gb, &si) < 0){
+    if(r->parse_slice_header(r, &r->s.gb, &si) < 0 || si.start){
         av_log(avctx, AV_LOG_ERROR, "First slice header is incorrect\n");
         return -1;
     }