diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 8bdec2f..37958df 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -16,20 +16,12 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macOS-13,   r: 'release'}
-          - {os: macOS-14,   r: 'release'}
-          - {os: macOS-latest,   r: 'release', disable-static: 'disable-static'}
+          - {os: windows-latest, r: '3.6'}
           - {os: windows-latest, r: '4.0'}
           - {os: windows-latest, r: '4.1'}
           - {os: windows-latest, r: '4.2'}
           - {os: windows-latest, r: '4.3'}
           - {os: windows-latest, r: '4.4'}
-          - {os: windows-2022,   r: 'devel'}
-          - {os: ubuntu-latest,  r: 'devel', http-user-agent: 'release'}
-          - {os: ubuntu-latest,  r: 'release'}
-          - {os: ubuntu-24.04,   r: 'release', disable-static: 'disable-static'}
-          - {os: ubuntu-22.04,   r: 'release', disable-static: 'disable-static'}
-          - {os: ubuntu-20.04,   r: 'release', disable-static: 'disable-static'}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}