diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index a4a47ee8e..3c9f88cfc 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -1899,7 +1899,7 @@ ngx_http_mp4_update_stts_atom(ngx_http_mp4_file_t *mp4,
         ngx_log_debug2(NGX_LOG_DEBUG_HTTP, mp4->file.log, 0,
                        "count:%uD, duration:%uD", count, duration);
 
-        if (start_time < count * duration) {
+        if (start_time < (uint64_t) count * duration) {
             start_sample += (ngx_uint_t) (start_time / duration);
             count -= start_sample;
             ngx_mp4_set_32value(entry->count, count);