diff --git a/ansible/playbooks/README.md b/ansible/playbooks/README.md
index 8449ffb0..f182c1e8 100644
--- a/ansible/playbooks/README.md
+++ b/ansible/playbooks/README.md
@@ -42,6 +42,7 @@ Before running the playbook, make sure the following settings are correct, and o
 | prefix_snapshot_url | Directory (served over http(s)) containing snapshot files |
 | prefix_snapshot_version | Date (`YYYYMMDD`) of the Portage snapshot file for the Prefix installation |
 | prefix_python_targets | String consisting of [Gentoo Python targets](https://wiki.gentoo.org/wiki/Project:Python/PYTHON_TARGETS) Python targets used for the Prefix installation |
+| prefix_user_defined_trusted_dir | Path to the user defined trusted dir for glibc |
 | prefix_singularity_command | Singularity command for launching the container with the bootstrap script |
 | prefix_source | Singularity container path used for the Prefix installtion |
 | prefix_source_options | Arguments to be passed to the Prefix bootstrap script |
diff --git a/ansible/playbooks/roles/compatibility_layer/defaults/main.yml b/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
index ed4e5c4f..593b44dd 100644
--- a/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
+++ b/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
@@ -19,6 +19,7 @@ gentoo_prefix_path: /cvmfs/{{ cvmfs_repository }}/{{ eessi_version }}/compat/{{
 prefix_snapshot_url: http://cvmfs-s0.eessi-hpc.org/snapshots
 prefix_snapshot_version: 20210222
 prefix_python_targets: python3_8
+prefix_user_defined_trusted_dir: /opt/eessi/lib
 prefix_singularity_command: "singularity run -B {{ gentoo_prefix_path }}:{{ gentoo_prefix_path }}"
 prefix_source: "docker://eessi/bootstrap-prefix:centos8-{{ eessi_host_arch }}"
 prefix_source_options: "{{ gentoo_prefix_path }} noninteractive"
diff --git a/ansible/playbooks/roles/compatibility_layer/tasks/add_overlay.yml b/ansible/playbooks/roles/compatibility_layer/tasks/add_overlay.yml
index 5503489e..28a81364 100644
--- a/ansible/playbooks/roles/compatibility_layer/tasks/add_overlay.yml
+++ b/ansible/playbooks/roles/compatibility_layer/tasks/add_overlay.yml
@@ -77,4 +77,3 @@
     force: yes
   with_items:
     "{{ find_configs.results | rejectattr('files', 'equalto', []) | map(attribute='files') | list }}"
-
diff --git a/ansible/playbooks/roles/compatibility_layer/tasks/install_packages.yml b/ansible/playbooks/roles/compatibility_layer/tasks/install_packages.yml
index 7d245297..c2d17992 100644
--- a/ansible/playbooks/roles/compatibility_layer/tasks/install_packages.yml
+++ b/ansible/playbooks/roles/compatibility_layer/tasks/install_packages.yml
@@ -1,5 +1,20 @@
 # Install a specified list of sets and packages.
 ---
+- name: Check if glibc has already been (re)installed with the user-defined-trusted-dirs option
+  command: "strings {{ gentoo_prefix_path }}/usr/lib64/libc.a"
+  register: glibc_reinstalled
+  when: eessi_host_os == "linux"
+
+- name: Reinstall glibc with the user-defined-trusted-dirs option
+  portage:
+    package: sys-libs/glibc
+    noreplace: no
+    oneshot: yes
+  become: no
+  environment:
+    EXTRA_EMAKE: "user-defined-trusted-dirs={{ prefix_user_defined_trusted_dir }}"
+  when: eessi_host_os == "linux" and glibc_reinstalled.stdout | regex_search("^" + prefix_user_defined_trusted_dir + "/?$")
+
 - name: Install package set {{ package_sets }}
   portage:
     package: "@{{ item }}"
diff --git a/ansible/playbooks/roles/compatibility_layer/tasks/main.yml b/ansible/playbooks/roles/compatibility_layer/tasks/main.yml
index 041a32b7..402c9d11 100644
--- a/ansible/playbooks/roles/compatibility_layer/tasks/main.yml
+++ b/ansible/playbooks/roles/compatibility_layer/tasks/main.yml
@@ -20,8 +20,6 @@
 - block:
   - include_tasks: prefix_configuration.yml
 
-  - include_tasks: create_host_symlinks.yml
-
   - include_tasks: add_overlay.yml
     args:
       apply:
@@ -31,6 +29,8 @@
 
   - include_tasks: install_packages.yml
 
+  - include_tasks: create_host_symlinks.yml
+
   - name: Publish transaction
     command: "cvmfs_server publish {{ cvmfs_repository }}"
     when: cvmfs_start_transaction and cvmfs_publish_transaction