diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index d0f6f64..313d6f4 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -18,6 +18,7 @@ jobs:
         config:
           - {os: windows-latest, r: 'release'}
           - {os: macOS-latest,   r: 'release'}
+          - {os: ubuntu-latest,   r: 'release'}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}