diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 5845e58b..68aa8738 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -26,7 +26,7 @@ jobs:
     #  os & python versions
     strategy:
       matrix:
-        os-name: [ ubuntu-latest, ubuntu-18.04, macOS-latest, windows-latest ]
+        os-name: [ ubuntu-latest, ubuntu-20.04, macOS-latest, windows-latest ]
         python-version: [ 3.9 ]
 #    needs: [ install-test ]
     steps: