diff --git a/requirements.txt b/requirements.txt
index d35b983..79987ab 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,7 +25,7 @@ git+git://github.com/RDFLib/rdflib@6cb0dabce15a0d5dc81954ecb833e31b47a68e28#egg=
 
 # frozen stable:
 appdirs==1.4.3
-cachetools==2.0.0
+cachetools==5.2.1
 certifi==2017.4.17
 chardet==3.0.3
 click==6.7