diff --git a/smm4h/requirements.txt b/smm4h/requirements.txt
index 45171f1..bda021a 100644
--- a/smm4h/requirements.txt
+++ b/smm4h/requirements.txt
@@ -113,7 +113,7 @@ tornado==4.5.3
 tqdm==4.23.4
 traitlets==4.3.2
 typing==3.6.2
-ujson==1.35
+ujson==5.4.0
 Unidecode==1.0.22
 urllib3==1.24.2
 wasabi==0.2.2