diff --git a/.circleci/config.yml b/.circleci/config.yml
index 45cc48dd..370ba804 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -8,7 +8,7 @@ commands:
   pip-install-deps-27:
     parameters:
       requirements:
-        default: "tests/requirements.txt"
+        default: "tests/requirements-27.txt"
         type: string
     steps:
       - run:
@@ -34,10 +34,11 @@ commands:
           command: |
             python -m venv venv
             . venv/bin/activate
+            pip install --upgrade pip
             pip install 'wheel>=0.29.0'
             pip install -r requirements.txt
             pip install -r <<parameters.requirements>>
-      
+
   install-couchbase-deps:
     steps:
       - run:
@@ -49,7 +50,7 @@ commands:
             sudo dpkg -i ./couchbase-release-1.0-6-amd64.deb
             sudo apt-get update
             sudo apt install libcouchbase-dev -y
-            
+
 jobs:
   python27:
     docker:
@@ -82,7 +83,7 @@ jobs:
     working_directory: ~/repo
     steps:
       - checkout
-      - pip-install-deps 
+      - pip-install-deps
       - run:
           name: run tests
           environment:
@@ -102,7 +103,7 @@ jobs:
     working_directory: ~/repo
     steps:
       - checkout
-      - pip-install-deps 
+      - pip-install-deps
       - run:
           name: run tests
           environment:
diff --git a/tests/clients/test_google-cloud-storage.py b/tests/clients/test_google-cloud-storage.py
index c3ec3243..be7ac15c 100644
--- a/tests/clients/test_google-cloud-storage.py
+++ b/tests/clients/test_google-cloud-storage.py
@@ -898,6 +898,7 @@ def test_batch_operation(self, mock_requests):
     def _client(self, *args, **kwargs):
         # override the HTTP client to bypass the authorization
         kwargs['_http'] = kwargs.get('_http', requests.Session())
+        kwargs['_http'].is_mtls = False
 
         return storage.Client(*args, **kwargs)
 
diff --git a/tests/requirements-27.txt b/tests/requirements-27.txt
new file mode 100644
index 00000000..186c833d
--- /dev/null
+++ b/tests/requirements-27.txt
@@ -0,0 +1,33 @@
+aiofiles>=0.5.0;python_version>="3.5"
+aiohttp>=3.5.4;python_version>="3.5"
+asynqp>=0.4;python_version>="3.5"
+boto3>=1.10.0
+celery>=4.1.1
+django>=1.11,<2.2
+fastapi>=0.61.1;python_version>="3.6"
+flask>=0.12.2
+grpcio>=1.18.0
+google-cloud-storage>=1.24.0;python_version>="3.5"
+lxml>=3.4
+mock>=2.0.0
+moto>=1.3.16,<2.0
+mysqlclient>=1.3.14;python_version>="3.5"
+MySQL-python>=1.2.5;python_version<="2.7"
+nose>=1.0
+PyMySQL[rsa]>=0.9.1
+pyOpenSSL>=16.1.0;python_version<="2.7"
+psycopg2>=2.7.1
+pika>=1.0.0
+pymongo>=3.7.0
+pyramid>=1.2
+pytest>=4.6
+pytest-celery
+redis>3.0.0
+requests>=2.17.1
+rsa<=4.5
+sqlalchemy>=1.1.15
+spyne>=2.9,<=2.12.14
+suds-jurko>=0.6
+tornado>=4.5.3,<6.0
+uvicorn>=0.12.2;python_version>="3.6"
+urllib3[secure]!=1.25.0,!=1.25.1,<1.26,>=1.21.1
diff --git a/tests/requirements.txt b/tests/requirements.txt
index a3090981..a6296e5d 100644
--- a/tests/requirements.txt
+++ b/tests/requirements.txt
@@ -10,7 +10,7 @@ grpcio>=1.18.0
 google-cloud-storage>=1.24.0;python_version>="3.5"
 lxml>=3.4
 mock>=2.0.0
-moto>=1.3.16
+moto>=1.3.16,<2.0
 mysqlclient>=1.3.14;python_version>="3.5"
 MySQL-python>=1.2.5;python_version<="2.7"
 nose>=1.0