diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index 0091bcc..6cdef08 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -23,25 +23,15 @@ jobs:
       matrix:
         config:
           - {os: macOS-latest,   r: 'release'}
-
           - {os: windows-latest, r: 'release'}
-          # Use 3.6 to trigger usage of RTools35
-          - {os: windows-latest, r: '3.6'}
-
-          # Use older ubuntu to maximise backward compatibility
-          - {os: ubuntu-20.04,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-20.04,   r: 'release'}
-          - {os: ubuntu-20.04,   r: 'oldrel-1'}
-          - {os: ubuntu-20.04,   r: 'oldrel-2'}
-          - {os: ubuntu-20.04,   r: 'oldrel-3'}
-          - {os: ubuntu-20.04,   r: 'oldrel-4'}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
       R_KEEP_PKG_SOURCE: yes
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - uses: r-lib/actions/setup-pandoc@v2