diff --git a/.github/workflows/R_CMD_check.yaml b/.github/workflows/R_CMD_check.yaml
index 4ea7b55..6eaab90 100644
--- a/.github/workflows/R_CMD_check.yaml
+++ b/.github/workflows/R_CMD_check.yaml
@@ -23,8 +23,8 @@ jobs:
       matrix:
         config:
           - {os: macOS-latest, r: 'release'}
-          # - {os: ubuntu-20.04, r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
-          # - {os: windows-latest, r: 'release'}  # Does not appear to have Java 32-bit, hence the --no-multiarch
+          - {os: ubuntu-20.04, r: 'release', rspm: "https://packagemanager.rstudio.com/cran/__linux__/focal/latest"}
+          - {os: windows-latest, r: 'release'}  # Does not appear to have Java 32-bit, hence the --no-multiarch
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true