diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index b54af84..a637189 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,7 @@ jobs:
 
   test_linux:
     name: Test (Linux)
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-20.04
     env:
       OS: Linux
     strategy:
diff --git a/pyfastani/tests/requirements.txt b/pyfastani/tests/requirements.txt
index 6096cca..a8bc2de 100644
--- a/pyfastani/tests/requirements.txt
+++ b/pyfastani/tests/requirements.txt
@@ -1,2 +1,2 @@
 biopython   ; implementation_name == "cpython"
-scikit-bio  ; implementation_name == "cpython" and python_version >= '3.8'
+# scikit-bio  ; implementation_name == "cpython" and python_version >= '3.8'