diff --git a/.github/workflows/ubuntu.yml b/.github/workflows/ubuntu.yml
index ffc2170b..49e0dbf5 100644
--- a/.github/workflows/ubuntu.yml
+++ b/.github/workflows/ubuntu.yml
@@ -29,6 +29,7 @@ jobs:
       fail-fast: false
       matrix:
         os:
+          - ubuntu-20.04
           - ubuntu-22.04
           - ubuntu-latest
         cxx_compiler: