diff --git a/requirements-dev-gaesdk.txt b/requirements-dev-gaesdk.txt
index f2bfad1..b71dc5b 100644
--- a/requirements-dev-gaesdk.txt
+++ b/requirements-dev-gaesdk.txt
@@ -4,7 +4,7 @@ Jinja2==2.6.0
 # The remaining requirements are defined by webapp2. These are the versions
 # that were used with release 2.5.2, except for babel.
 six==1.10.0
-Mako==0.4.1
+Mako==1.2.2
 Babel==2.2
 gaepytz==2011h
 # Test dependencies.
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 648d555..39b7a34 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -1,7 +1,7 @@
 # These dependencies match App Engine SDK versions.
 WebOb==1.6.1
 Jinja2==2.8
-Mako==1.0.4
+Mako==1.2.2
 Babel==2.3.4
 pytz==2016.6.1
 # These are test dependencies