diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index db55e8d..93f695d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -20,8 +20,8 @@ jobs:
       USING_COVERAGE: "3.7,3.8,3.9,3.10,3.11"
     strategy:
       matrix:
-#        os: ["ubuntu-18.04", "windows-latest"]
-        os: ["ubuntu-18.04", ] # for debug only
+        os: ["ubuntu-latest", "windows-latest"]
+#        os: ["ubuntu-latest", ] # for debug only
         python-version: [3.7", "3.8", "3.9", "3.10", "3.11"]
 #        python-version: ["3.7", ] # for debug only
         exclude: