diff --git a/.github/workflows/minimal-usage.yml b/.github/workflows/minimal-usage.yml
index 16a0788..694db84 100644
--- a/.github/workflows/minimal-usage.yml
+++ b/.github/workflows/minimal-usage.yml
@@ -30,6 +30,26 @@ jobs:
       shell: bash
     - name: Test available repos
       run: |
+        # Make sure an EESSI module is loaded
+        module list |& grep "EESSI/"
         ls /cvmfs/software.eessi.io
         ls /cvmfs/dev.eessi.io
       shell: bash
+
+  test_mount_only:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: ./
+      with:
+        mount_cvmfs_only: 'true'
+        init_direnv: 'false'
+    - name: Test EESSI not initialised
+      run: |
+        if [[ -v EESSI_VERSION ]]; then
+          echo "EESSI_VERSION should not be set as this indicates EESSI is initialised"
+          exit 1
+        fi
+        # Make sure CVMFS is mounted, and EESSI available
+        ls /cvmfs/software.eessi.io
+      shell: bash
diff --git a/.github/workflows/minimal_usage_lmod_init.yml b/.github/workflows/minimal_usage_bash_init.yml
similarity index 72%
rename from .github/workflows/minimal_usage_lmod_init.yml
rename to .github/workflows/minimal_usage_bash_init.yml
index 7adb970..bc925a7 100644
--- a/.github/workflows/minimal_usage_lmod_init.yml
+++ b/.github/workflows/minimal_usage_bash_init.yml
@@ -1,4 +1,4 @@
-name: ubuntu-minimal_usage-lmod_init
+name: ubuntu-minimal_usage-bash_script_init
 on:
   schedule:
     - cron: '0 0 * * *'  # Runs once a day at midnight UTC
@@ -12,7 +12,7 @@ on:
 # Declare default permissions as read only.
 permissions: read-all
 jobs:
-  minimal_usage:
+  minimal_usage_bash_script:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -24,12 +24,17 @@ jobs:
     - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - uses: ./
       with:
-        use_eessi_module: true
+        use_eessi_module: false
         init_direnv: false
     - name: Test EESSI
       run: |
         module avail
-        module list |& grep "EESSI/"
+        if ! module list |& grep -q "EESSI/"; then
+          echo "EESSI module is NOT loaded"
+        else
+          echo "EESSI module is loaded but shouldn't be"
+          exit 1
+        fi
       shell: bash
     - name: Test available repos
       run: |
diff --git a/README.md b/README.md
index 7401333..68a9a8f 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,8 @@ jobs:
     steps:
     - uses: actions/checkout@v6
     - uses: eessi/github-action-eessi@v3
+      with:
+        eessi_stack_version: '2025.06'
     - name: Test EESSI
       run: |
         module avail
@@ -65,7 +67,10 @@ jobs:
 ## Optional Parameters
 The following parameters are supported:
 - `eessi_stack_version`: version of the EESSI stack to use (defaults to `2023.06`)
-- `eessi_config_package`: location of the EESSI CernVM-FS configuration package (defaults to `https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi_latest_all.deb`). 
+- `eessi_repositories`: Comma separated list of EESSI repositories to make available (defaults to `software.eessi.io,dev.eessi.io`).
+- `use_eessi_module`: Use the Lmod method to initialise EESSI (defaults to `true`)
+- `mount_cvmfs_only`: Only mount the EESSI CernVM-FS repositories, do not initialise EESSI (defaults to `false`)
+- `init_direnv`: Initialise direnv for the repository (defaults to `true`)
 <!--For macOS this parameter is required (e.g., `https://github.com/EESSI/filesystem-layer/releases/download/latest/cvmfs-config-eessi_latest_all.pkg`) -->
 
 ## Minimal Example
diff --git a/action.yml b/action.yml
index a015f66..8507083 100644
--- a/action.yml
+++ b/action.yml
@@ -15,6 +15,10 @@ inputs:
   use_eessi_module:
     description: 'Use the EESSI module to initialise EESSI (rather than sourcing a bash script), valid values are true or false'
     required: false
+    default: 'true'
+  mount_cvmfs_only:
+    description: 'Only mount CVMFS, do not initialise EESSI'
+    required: false
     default: 'false'
   init_direnv:
     description: 'Enable direnv initialisation for the repository, valid values are true or false'
@@ -31,13 +35,27 @@ runs:
         cvmfs_http_proxy: DIRECT
         cvmfs_repositories: 'cvmfs-config.cern.ch,${{ inputs.eessi_repositories }}'
     - id: install-eessi
+      shell: bash
+      env:
+        EESSI_STACK_VERSION: ${{ inputs.eessi_stack_version }}
+        ALLOWED_VERSIONS: "2023.06 2025.06"
       run: |
         if [ "$RUNNER_OS" == "Linux" ]; then
           echo 'unset BASH_ENV' >> $HOME/env_config.export
-          if [[ "${{ inputs.use_eessi_module }}" == "true" ]]; then
-            echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/lmod/bash" >> $HOME/env_config.export
-          else
-            echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/bash" >> $HOME/env_config.export
+          if [[ "${{ inputs.mount_cvmfs_only }}" == "false" ]]; then
+            [[ " $ALLOWED_VERSIONS " =~ " $EESSI_STACK_VERSION " ]] || {
+              echo "Invalid eessi_stack_version: '$EESSI_STACK_VERSION'"
+              echo "Allowed values: $ALLOWED_VERSIONS"
+              exit 1
+            }
+            if [[ "${{ inputs.use_eessi_module }}" == "true" ]]; then
+              # Make the EESSI module sticky so that it persists in case `module purge` is used
+              # (while still allowing for a swap if needed)
+              echo "export EESSI_MODULE_STICKY=1" >> $HOME/env_config.export
+              echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/lmod/bash" >> $HOME/env_config.export
+            else
+              echo "source /cvmfs/software.eessi.io/versions/$EESSI_STACK_VERSION/init/bash" >> $HOME/env_config.export
+            fi
           fi
           # allow oversubscription for OpenMPI
           echo "export OMPI_MCA_rmaps_base_oversubscribe=1" >> $HOME/env_config.export
@@ -62,7 +80,3 @@ runs:
           # limactl start eessi || true
           # cat /Users/runner/.lima/eessi/ha.stderr.log
         fi
-      shell: bash
-      env:
-        EESSI_STACK_VERSION: ${{ inputs.eessi_stack_version }}
-