diff --git a/src/demux/demux.c b/src/demux/demux.c
index f04a2b84..12fe5ca0 100644
--- a/src/demux/demux.c
+++ b/src/demux/demux.c
@@ -614,7 +614,6 @@ static int IsValidExtendedFormat(const WebPDemuxer* const dmux) {
 
   while (f != NULL) {
     const int cur_frame_set = f->frame_num_;
-    int frame_count = 0;
 
     // Check frame properties.
     for (; f != NULL && f->frame_num_ == cur_frame_set; f = f->next_) {
@@ -649,8 +648,6 @@ static int IsValidExtendedFormat(const WebPDemuxer* const dmux) {
                             dmux->canvas_width_, dmux->canvas_height_)) {
         return 0;
       }
-
-      ++frame_count;
     }
   }
   return 1;