diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 49c7756..31d9668 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -19,7 +19,9 @@ jobs:
       matrix:
         config:
           - {os: macos-latest,   r: 'release'}
+          - {os: macos-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: windows-latest, r: 'release'}
+          - {os: windows-latest, r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'release'}
           - {os: ubuntu-latest,   r: 'oldrel-1'}