diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index ee65ccb..d10a3a5 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -22,20 +22,20 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macos-latest,   r: 'release'}
+          # - {os: macos-latest,   r: 'release'}
 
           - {os: windows-latest, r: 'release'}
           # Use 3.6 to trigger usage of RTools35
-          - {os: windows-latest, r: '3.6'}
+          # - {os: windows-latest, r: '3.6'}
           # use 4.1 to check with rtools40's older compiler
-          - {os: windows-latest, r: '4.1'}
-
-          - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
-          - {os: ubuntu-latest,   r: 'release'}
-          - {os: ubuntu-latest,   r: 'oldrel-1'}
-          - {os: ubuntu-latest,   r: 'oldrel-2'}
-          - {os: ubuntu-latest,   r: 'oldrel-3'}
-          - {os: ubuntu-latest,   r: 'oldrel-4'}
+          # - {os: windows-latest, r: '4.1'}
+
+          # - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
+          # - {os: ubuntu-latest,   r: 'release'}
+          # - {os: ubuntu-latest,   r: 'oldrel-1'}
+          # - {os: ubuntu-latest,   r: 'oldrel-2'}
+          # - {os: ubuntu-latest,   r: 'oldrel-3'}
+          # - {os: ubuntu-latest,   r: 'oldrel-4'}
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}