diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8b8da18..f27df5c 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -24,9 +24,8 @@ jobs:
       name: Set CONDA_ROOT
       run: |
           CONDA_ROOT=$(dirname $GITHUB_WORKSPACE)/conda
-          echo "::set-output name=value::$CONDA_ROOT"
+          echo "value=$CONDA_ROOT" >> $GITHUB_OUTPUT
           echo "CONDA_ROOT=$CONDA_ROOT" >> $GITHUB_ENV
-          echo "CONDA_ROOT: $CONDA_ROOT"
     # Use a smaller cache entry to enable a quicker exit if we
     # have already built the testbed. Any small file will do
     - id: cache-key
@@ -42,6 +41,12 @@ jobs:
       with:
         path: ${{ steps.conda-root.outputs.value }}
         key: testbed-${{ matrix.os }}-${{ hashFiles('testbed') }}
+    - name: Install Miniconda
+      uses: conda-incubator/setup-miniconda@v3
+      if: steps.cache-key.outputs.cache-hit != 'true'
+      with:
+        auto-activate-base: true
+        activate-environment: ""
     - name: Verify or build the testbed
       if: steps.cache-key.outputs.cache-hit != 'true'
       # The argument tells the script we are in caching mode
diff --git a/testbed/build.sh b/testbed/build.sh
index dfd4d46..d658e99 100755
--- a/testbed/build.sh
+++ b/testbed/build.sh
@@ -23,7 +23,7 @@ function full_deactivate {
 
 # Skip creation if the cached version is available
 if [ ! -d $CONDA_ROOT/conda-meta ]; then
-    ${CONDA_EXE:-conda} env create -f $cwd/croot.yml -p $CONDA_ROOT
+    ${CONDA_EXE:-conda} env create --file=$cwd/croot.yml -p $CONDA_ROOT
     if [[ "$RUNNER_OS" == "" && "$OS" == "Windows_NT" ]]; then
         conda install -y -p $CONDA_ROOT m2-bash m2-coreutils m2-filesystem
     fi
@@ -41,10 +41,11 @@ if [ ! -f $CONDA_ROOT/.created ]; then
     # including an R kernel, a Python kernel, and environment names with at
     # least one non-ASCII character and one space. We also need one environment
     # installed in a non-default environment location.
-    conda env create -f $cwd/testenv1.yaml
-    conda env create -f $cwd/testenv2.yaml
+    conda config --prepend channels conda-forge --system
+    conda env create --file=$cwd/testenv1.yaml
+    conda env create --file=$cwd/testenv2.yaml
     mkdir -p $CONDA_ROOT/ext1/ext2/env
-    conda env create -f $cwd/testenv1.yaml -p $CONDA_ROOT/ext1/ext2/env/test_env1
+    conda env create --file=$cwd/testenv1.yaml -p $CONDA_ROOT/ext1/ext2/env/test_env1
     rm -rf $CONDA_ROOT/pkgs
 
     touch $CONDA_ROOT/.created