diff --git a/.github/workflows/R-CMD-check.yaml b/.github/workflows/R-CMD-check.yaml
index ee65ccb..16ef516 100644
--- a/.github/workflows/R-CMD-check.yaml
+++ b/.github/workflows/R-CMD-check.yaml
@@ -23,13 +23,9 @@ 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 4.1 to check with rtools40's older compiler
+          - {os: windows-latest, r: '4.2', rtools: '42'}
           - {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'}
@@ -49,6 +45,7 @@ jobs:
       - uses: r-lib/actions/setup-r@v2
         with:
           r-version: ${{ matrix.config.r }}
+          rtools-version: ${{ matrix.config.rtools }}
           http-user-agent: ${{ matrix.config.http-user-agent }}
           use-public-rspm: true
 
diff --git a/src/Makevars.ucrt b/src/Makevars.ucrt
index 52910e3..2ac7d52 100644
--- a/src/Makevars.ucrt
+++ b/src/Makevars.ucrt
@@ -1,4 +1 @@
-CXX_STD = CXX11
-
-CRT = -ucrt
-include Makevars.win
+PKG_LIBS = -lpng -lz