diff --git a/.github/workflows/R-CMD-check-macOS.yml b/.github/workflows/R-CMD-check-macOS.yml
index 3607e53..9ea3999 100644
--- a/.github/workflows/R-CMD-check-macOS.yml
+++ b/.github/workflows/R-CMD-check-macOS.yml
@@ -20,8 +20,12 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - {os: macOS-latest,   r: '4.1.2'}
+          #- {os: macOS-latest,   r: '4.1.2'} # incompatible versions of gfortran and  R
           - {os: macOS-latest,   r: 'release'}
+          - {os: macOS-13,   r: '4.1.2'}
+          - {os: macOS-13,   r: 'release'}
+          - {os: macOS-12,   r: '4.1.2'}
+          - {os: macOS-12,   r: 'release'}
 
     env:
       R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
diff --git a/.github/workflows/R-CMD-check-ubuntu.yml b/.github/workflows/R-CMD-check-ubuntu.yml
deleted file mode 100644
index 1308c9d..0000000
--- a/.github/workflows/R-CMD-check-ubuntu.yml
+++ /dev/null
@@ -1,55 +0,0 @@
-##############################################################################
-# GitHub Actions Workflow to test the R interface of volesti
-#
-# Copyright (c) 2020 Vissarion Fisikopoulos
-#
-# Licensed under GNU LGPL.3, see LICENCE file
-##############################################################################
-
-on: [push, pull_request]
-
-name: R-CMD-check-ubuntu
-
-jobs:
-  R-CMD-check:
-    runs-on: ${{ matrix.config.os }}
-
-    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
-
-    strategy:
-      fail-fast: false
-      matrix:
-        config:
-         - {os: ubuntu-latest,  r: 'devel'}
-         - {os: ubuntu-latest,  r: 'release'}
-
-    env:
-      R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
-      RSPM: ${{ matrix.config.rspm }}
-      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
-
-    steps:
-      - uses: actions/checkout@v3
-      - run: sudo apt-get update || true;
-             sudo apt install build-essential libcurl4-gnutls-dev libxml2-dev libssl-dev libgit2-dev libfontconfig1-dev libharfbuzz-dev libfribidi-dev;
-
-      - uses: r-lib/actions/setup-r@v2
-        with:
-          r-version: ${{ matrix.config.r }}
-
-      - uses: r-lib/actions/setup-pandoc@v2
-
-      - name: Install dependencies
-        run: Rscript -e "install.packages(c('testthat', 'pkgload', 'rcmdcheck', 'devtools', 'Rcpp', 'RcppEigen', 'BH', 'downloader', 'xfun', dependencies=TRUE))";
-
-      - name: Check
-        env:
-          _R_CHECK_CRAN_INCOMING_REMOTE_: false
-        run: Rscript -e "library(rcmdcheck)" -e "rcmdcheck::rcmdcheck(args = c('--no-manual'), error_on = 'warning', check_dir = 'check')"
-
-      - name: Upload check results
-        if: failure()
-        uses: actions/upload-artifact@v4
-        with:
-          name: ${{ runner.os }}-r${{ matrix.config.r }}-results
-          path: check
diff --git a/.github/workflows/R-CMD-check-windows.yml b/.github/workflows/R-CMD-check-windows.yml
deleted file mode 100644
index c40657f..0000000
--- a/.github/workflows/R-CMD-check-windows.yml
+++ /dev/null
@@ -1,52 +0,0 @@
-##############################################################################
-# GitHub Actions Workflow to test the R interface of volesti
-#
-# Copyright (c) 2020 Vissarion Fisikopoulos
-#
-# Licensed under GNU LGPL.3, see LICENCE file
-##############################################################################
-
-on: [push, pull_request]
-
-name: R-CMD-check-windows
-
-jobs:
-  R-CMD-check:
-    runs-on: ${{ matrix.config.os }}
-
-    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
-
-    strategy:
-      fail-fast: false
-      matrix:
-        config:
-          - {os: windows-latest, r: 'release'}
-
-    env:
-      R_REMOTES_NO_ERRORS_FROM_WARNINGS: true
-      RSPM: ${{ matrix.config.rspm }}
-      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
-
-    steps:
-      - uses: actions/checkout@v3
-
-      - uses: r-lib/actions/setup-r@v2
-        with:
-          r-version: ${{ matrix.config.r }}
-
-      - uses: r-lib/actions/setup-pandoc@v2
-
-      - name: Install dependencies
-        run: Rscript -e "install.packages(c('devtools', dependencies=TRUE))" -e "install.packages(c('rcmdcheck', 'devtools', 'Rcpp', 'RcppEigen', 'BH', 'testthat', 'downloader', 'xfun'))"
-
-      - name: Check
-        env:
-          _R_CHECK_CRAN_INCOMING_REMOTE_: false
-        run: Rscript -e "library(rcmdcheck)" -e "rcmdcheck::rcmdcheck(args = c('--no-manual'), error_on = 'warning', check_dir = 'check')"
-
-      - name: Upload check results
-        if: failure()
-        uses: actions/upload-artifact@v4
-        with:
-          name: ${{ runner.os }}-r${{ matrix.config.r }}-results
-          path: check