diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index fd65c11c..05445774 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -9,12 +9,11 @@ on:
 
 jobs:
   test:
-    runs-on: ${{ matrix.os }}
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: true
       matrix:
-        os: ["ubuntu-latest", "macos-latest"]
-        python-version: ["3.6", "3.8", "3.9"]
+        python-version: ["3.5", "3.6", "3.7", "3.8", "3.9"]
 
     steps:
       - name: Checkout source