diff --git a/libavcodec/mpeg4videodec.c b/libavcodec/mpeg4videodec.c
index 8064f1eb40..1776efa9ae 100644
--- a/libavcodec/mpeg4videodec.c
+++ b/libavcodec/mpeg4videodec.c
@@ -2967,6 +2967,7 @@ static int decode_studio_vop_header(Mpeg4DecContext *ctx, GetBitContext *gb)
     if (get_bits_left(gb) <= 32)
         return 0;
 
+    s->partitioned_frame = 0;
     s->decode_mb = mpeg4_decode_studio_mb;
 
     decode_smpte_tc(ctx, gb);