diff --git a/requirements.txt b/requirements.txt
index 09a6cc2..cdc0ecc 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -29,7 +29,7 @@ simplejson==3.17.2
 six==1.15.0
 transaction==3.0.0
 translationstring==1.4
-ujson==3.2.0
+ujson==4.0.0
 urllib3==1.25.10
 venusian==3.0.0
 waitress==1.4.4