diff --git a/r.txt b/r.txt
index 36e57a3c..1162098d 100644
--- a/r.txt
+++ b/r.txt
@@ -136,7 +136,7 @@ tornado==5.0.2
 tqdm==4.24.0
 traitlets==4.3.2
 typing_extensions==4.0.1
-ujson==1.35
+ujson==5.2.0
 update==0.0.1
 urllib3==1.24.2
 uWSGI==2.0.15
diff --git a/requirements.txt b/requirements.txt
index 5cf716d1..cc6f2f48 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -106,7 +106,7 @@ toolz==0.9.0
 tornado==5.0.2
 tqdm==4.24.0
 traitlets==4.3.2
-ujson==1.35
+ujson==5.2.0
 update==0.0.1
 urllib3==1.24.2
 uWSGI==2.0.15