diff --git a/requirements.txt b/requirements.txt
index 2342ee1..9d565be 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ cachetools==3.1.1
 google-api-python-client==1.7.10
 google-auth==1.6.3
 google-auth-httplib2==0.0.3
-httplib2==0.13.1
+httplib2==0.18.0
 oauth2client==4.1.3
 pyasn1==0.4.6
 pyasn1-modules==0.2.6