diff --git a/.travis.yml b/.travis.yml
index 86a0d3e7d..96e28b1b0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,11 +2,12 @@ language: python
 
 services:
   - rabbitmq
+  - mariadb
 
 # http://docs.travis-ci.com/user/ci-environment/#CI-environment-OS
 # gimme has to be kept in sync with Boulder's Go version setting in .travis.yml
 before_install:
-  - sudo apt-get install -y mariadb-server mariadb-server-10.0
+  - 'dpkg -s libaugeas0'
   - '[ "xxx$BOULDER_INTEGRATION" = "xxx" ] || eval "$(gimme 1.5.1)"'
 
 # using separate envs with different TOXENVs creates 4x1 Travis build
@@ -31,9 +32,8 @@ branches:
     - master
     - /^test-.*$/
 
-# enable Trusty beta on travis 
-sudo: required
-dist: trusty
+# container-based infrastructure
+sudo: false
 
 addons:
   # make sure simplehttp simple verification works (custom /etc/hosts)
@@ -41,6 +41,8 @@ addons:
     - le.wtf
   mariadb: "10.0"
   apt:
+    sources:
+    - augeas
     packages:  # keep in sync with bootstrap/ubuntu.sh and Boulder
     - python
     - python-dev
diff --git a/acme/acme/jose/jwa.py b/acme/acme/jose/jwa.py
index 4ce5ca3f5..1853e0107 100644
--- a/acme/acme/jose/jwa.py
+++ b/acme/acme/jose/jwa.py
@@ -176,5 +176,5 @@ PS384 = JWASignature.register(_JWAPS('PS384', hashes.SHA384))
 PS512 = JWASignature.register(_JWAPS('PS512', hashes.SHA512))
 
 ES256 = JWASignature.register(_JWAES('ES256'))
-ES256 = JWASignature.register(_JWAES('ES384'))
-ES256 = JWASignature.register(_JWAES('ES512'))
+ES384 = JWASignature.register(_JWAES('ES384'))
+ES512 = JWASignature.register(_JWAES('ES512'))
diff --git a/letsencrypt-nginx/letsencrypt_nginx/configurator.py b/letsencrypt-nginx/letsencrypt_nginx/configurator.py
index 0123ac321..d97cf7397 100644
--- a/letsencrypt-nginx/letsencrypt_nginx/configurator.py
+++ b/letsencrypt-nginx/letsencrypt_nginx/configurator.py
@@ -107,6 +107,10 @@ class NginxConfigurator(common.Plugin):
     # This is called in determine_authenticator and determine_installer
     def prepare(self):
         """Prepare the authenticator/installer."""
+        # Verify Nginx is installed
+        if not le_util.exe_exists(self.conf('ctl')):
+            raise errors.NoInstallationError
+
         self.parser = parser.NginxParser(
             self.conf('server-root'), self.mod_ssl_conf)
 
diff --git a/letsencrypt-nginx/letsencrypt_nginx/dvsni.py b/letsencrypt-nginx/letsencrypt_nginx/dvsni.py
index b388c0267..8fd705f08 100644
--- a/letsencrypt-nginx/letsencrypt_nginx/dvsni.py
+++ b/letsencrypt-nginx/letsencrypt_nginx/dvsni.py
@@ -99,8 +99,8 @@ class NginxDvsni(common.TLSSNI01):
         for key, body in main:
             if key == ['http']:
                 found_bucket = False
-                for key, _ in body:
-                    if key == bucket_directive[0]:
+                for k, _ in body:
+                    if k == bucket_directive[0]:
                         found_bucket = True
                 if not found_bucket:
                     body.insert(0, bucket_directive)
diff --git a/letsencrypt-nginx/letsencrypt_nginx/tests/configurator_test.py b/letsencrypt-nginx/letsencrypt_nginx/tests/configurator_test.py
index 7000f85dc..913c5de27 100644
--- a/letsencrypt-nginx/letsencrypt_nginx/tests/configurator_test.py
+++ b/letsencrypt-nginx/letsencrypt_nginx/tests/configurator_test.py
@@ -1,3 +1,4 @@
+# pylint: disable=too-many-public-methods
 """Test for letsencrypt_nginx.configurator."""
 import os
 import shutil
@@ -29,6 +30,12 @@ class NginxConfiguratorTest(util.NginxTest):
         shutil.rmtree(self.config_dir)
         shutil.rmtree(self.work_dir)
 
+    @mock.patch("letsencrypt_nginx.configurator.le_util.exe_exists")
+    def test_prepare_no_install(self, mock_exe_exists):
+        mock_exe_exists.return_value = False
+        self.assertRaises(
+            errors.NoInstallationError, self.config.prepare)
+
     def test_prepare(self):
         self.assertEquals((1, 6, 2), self.config.version)
         self.assertEquals(5, len(self.config.parser.parsed))
diff --git a/letsencrypt-nginx/letsencrypt_nginx/tests/util.py b/letsencrypt-nginx/letsencrypt_nginx/tests/util.py
index cb4e08ddf..e60feb3d3 100644
--- a/letsencrypt-nginx/letsencrypt_nginx/tests/util.py
+++ b/letsencrypt-nginx/letsencrypt_nginx/tests/util.py
@@ -49,21 +49,25 @@ def get_nginx_configurator(
 
     backups = os.path.join(work_dir, "backups")
 
-    config = configurator.NginxConfigurator(
-        config=mock.MagicMock(
-            nginx_server_root=config_path,
-            le_vhost_ext="-le-ssl.conf",
-            config_dir=config_dir,
-            work_dir=work_dir,
-            backup_dir=backups,
-            temp_checkpoint_dir=os.path.join(work_dir, "temp_checkpoints"),
-            in_progress_dir=os.path.join(backups, "IN_PROGRESS"),
-            server="https://acme-server.org:443/new",
-            tls_sni_01_port=5001,
-        ),
-        name="nginx",
-        version=version)
-    config.prepare()
+    with mock.patch("letsencrypt_nginx.configurator.le_util."
+            "exe_exists") as mock_exe_exists:
+        mock_exe_exists.return_value = True
+
+        config = configurator.NginxConfigurator(
+            config=mock.MagicMock(
+                nginx_server_root=config_path,
+                le_vhost_ext="-le-ssl.conf",
+                config_dir=config_dir,
+                work_dir=work_dir,
+                backup_dir=backups,
+                temp_checkpoint_dir=os.path.join(work_dir, "temp_checkpoints"),
+                in_progress_dir=os.path.join(backups, "IN_PROGRESS"),
+                server="https://acme-server.org:443/new",
+                tls_sni_01_port=5001,
+            ),
+            name="nginx",
+            version=version)
+        config.prepare()
 
     # Provide general config utility.
     nsconfig = configuration.NamespaceConfig(config.config)