diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index e3d69070e..0d9c0d8e5 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.8]
+        python-version: [3.7, 3.8]
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python-version }}
diff --git a/Dockerfile b/Dockerfile
index b9ef23da3..9e53a6195 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.8-slim
+FROM python:3.7-slim
 
 WORKDIR /app
 COPY requirements.txt /app/
diff --git a/Pipfile b/Pipfile
index 5c5ff97a9..ffe18fd75 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,7 +4,7 @@ url = "https://pypi.org/simple"
 verify_ssl = true
 
 [requires]
-python_version = "3.8"
+python_version = "3.7"
 
 [packages]
 bitstring = "*"
diff --git a/requirements.txt b/requirements.txt
index e81d76625..247b81dce 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -21,6 +21,7 @@ pyscss==1.3.7
 requests==2.24.0
 shortuuid==1.0.1
 six==1.15.0; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'
+typing-extensions==3.7.4.3; python_version < '3.8'
 urllib3==1.25.10; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4' and python_version < '4'
 webassets==2.0
 werkzeug==1.0.1; python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'