diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index b2ebad68..0cbf1669 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -18,8 +18,8 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macOS-latest,   r: 'release'}
-          - {os: windows-latest, r: 'release'}
+          - {os: macOS-13,   r: 'release'}
+          - {os: windows-2022, r: 'release'}
           - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
           - {os: ubuntu-latest,   r: 'release'}
           - {os: ubuntu-latest,   r: 'oldrel-1'}
@@ -29,7 +29,7 @@ jobs:
       R_KEEP_PKG_SOURCE: yes
 
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
 
       - uses: r-lib/actions/setup-pandoc@v2
 
@@ -40,9 +40,18 @@ jobs:
           use-public-rspm: true
 
       - uses: r-lib/actions/setup-r-dependencies@v2
+        id: install-deps
+        continue-on-error: true
         with:
           extra-packages: any::rcmdcheck
           needs: check
+      
+      - name: If source build fails on macOS or Windows, fall back to typical install
+        if: steps.install-deps.outcome == 'failure'
+        shell: Rscript {0}
+        run: |
+          reticulate::install_miniconda()
+          install.packages("synapser", repos="http://ran.synapse.org")
 
       - uses: r-lib/actions/check-r-package@v2
         with: