diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index f4575ce6..1d6caf96 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -7,8 +7,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
+        os: [ubuntu-18.04, ubuntu-16.04, windows-2019, windows-2016, macOS-10.14, macOS-10.13]
         python-version: [3.5, 3.6, 3.7]
-        os: [ubuntu-latest, ubuntu-12.04, ubuntu-14.04, ubuntu-16.04, windows-latest, macOS-latest, macOS-10.12]
     steps:
     - uses: actions/checkout@v1
     - name: Set up $(( matrix.runs-on )) Python ${{ matrix.python-version }}