diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 750e3e0fbe..400e0d9cd8 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -683,7 +683,7 @@ frame_end:
         int current_pos= s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb)>>3);
         int startcode_found=0;
 
-        if(buf_size - current_pos > 5){
+        if(buf_size - current_pos > 7){
             int i;
             for(i=current_pos; i<buf_size-4; i++){
                 if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){