diff --git a/YOPO_preprocessing/requirements.txt b/YOPO_preprocessing/requirements.txt
index 69fe42e..90803ec 100644
--- a/YOPO_preprocessing/requirements.txt
+++ b/YOPO_preprocessing/requirements.txt
@@ -3,7 +3,7 @@ MarkupSafe == 1
 Pygments == 2.2.0
 appdirs == 1.4.3
 appnope == 0.1.0
-bleach == 2.1.2
+bleach == 3.1.4
 cycler == 0.10.0
 decorator == 4.2.1
 entrypoints == 0.2.3