diff --git a/requirements.txt b/requirements.txt
index a187d5ac1..ef2a2b646 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,4 +4,4 @@ nose-cov==1.6
 chai==1.1.1
 sphinx==1.3.5
 simplejson==3.6.5
-backports.functools_lru_cache==1.2.1
+backports.functools_lru_cache>=1.2.1,<1.4