diff --git a/src/http/modules/ngx_http_mp4_module.c b/src/http/modules/ngx_http_mp4_module.c
index 9c3f627fed7..5721efbe609 100644
--- a/src/http/modules/ngx_http_mp4_module.c
+++ b/src/http/modules/ngx_http_mp4_module.c
@@ -2331,7 +2331,7 @@ ngx_http_mp4_crop_stts_data(ngx_http_mp4_file_t *mp4,
         }
 
         start_sample += count;
-        start_time -= count * duration;
+        start_time -= (uint64_t) count * duration;
         entries--;
         entry++;
     }