diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8d46436..61245e8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,5 +1,5 @@
 name: Test
-on: ["push", "pull_request"]
+on: ["pull_request"]
 jobs:
   lint:
     runs-on: ubuntu-latest
@@ -8,7 +8,7 @@ jobs:
       uses: actions/checkout@v2
     - uses: actions/setup-python@v1
       with:
-        python-version: 3.7
+        python-version: 3.9
     - name: Install flake8
       run: pip install flake8 flake8-import-order
     - name: Flake8
@@ -18,7 +18,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.7]
+        python-version: [3.9]
     steps:
     - name: Checkout
       uses: actions/checkout@v2
@@ -46,7 +46,7 @@ jobs:
       uses: actions/checkout@v2
     - uses: actions/setup-python@v1
       with:
-        python-version: 3.7
+        python-version: 3.9
     - name: Python install
       run: pip install -U pip setuptools nose build
     - name: Build a binary wheel and a source tarball
diff --git a/requirements.txt b/requirements.txt
index 9b7e3ce..6fbcc07 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 requests
-biopython>=1.77
+biopython>=1.77,<=1.81
 cachetools<4
 click>=6.7
 wrapt
diff --git a/setup.py b/setup.py
index 1033e0c..e4cc11f 100644
--- a/setup.py
+++ b/setup.py
@@ -35,5 +35,5 @@
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
         "Topic :: Scientific/Engineering",
-        'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.9',
     ])