diff --git a/libavcodec/aac_ac3_parser.c b/libavcodec/aac_ac3_parser.c
index d0c912a606..20a989767c 100644
--- a/libavcodec/aac_ac3_parser.c
+++ b/libavcodec/aac_ac3_parser.c
@@ -51,7 +51,7 @@ get_next:
             }else{
                 i-= s->header_size -1;
                 s->remaining_size = len;
-                if(!new_frame_start){
+                if(!new_frame_start || pc->index+i<=0){
                     s->remaining_size += i;
                     goto get_next;
                 }