diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 772c87b..d2b35b4 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-18.04, ubuntu-20.04]
+        os: [ubuntu-20.04]
         python:
           - "3.6"
           - "3.7"