diff --git a/ansible/playbooks/roles/compatibility_layer/defaults/main.yml b/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
index 99501e22..847f8ac3 100644
--- a/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
+++ b/ansible/playbooks/roles/compatibility_layer/defaults/main.yml
@@ -1,11 +1,11 @@
 # Defaults file for the compatibility layer role.
 ---
-eessi_version: "2023.04"
+eessi_version: "2023.06"
 
 custom_overlays:
   - name: eessi
     source: git
-    url: https://github.com/EESSI/gentoo-overlay.git
+    url: https://github.com/trz42/gentoo-overlay.git
     eclass-overrides: true
 
 cvmfs_repository: pilot.eessi-hpc.org
@@ -26,6 +26,10 @@ prefix_mask_packages: |
   # stick to GCC 9.x; using a too recent compiler in the compat layer complicates stuff in the software layer,
   # see for example https://github.com/EESSI/software-layer/issues/151
   >=sys-devel/gcc-10
+  # mask OpenSSL 3.x, stick to OpenSSL 1.1.x for now to avoid problems with:
+  # - older versions of Rust (see https://github.com/EESSI/software-layer/issues/257)
+  # - older versions of cryptograhy in Python (see https://github.com/EESSI/software-layer/issues/258)
+  >=dev-libs/openssl-3
 prefix_unmask_packages: |
   # unmask older GCC to make it installable
   =sys-devel/gcc-9*
diff --git a/bot/build.sh b/bot/build.sh
index 9995db52..0bc2584b 100755
--- a/bot/build.sh
+++ b/bot/build.sh
@@ -81,7 +81,7 @@ host_arch=$(uname -m)
 eessi_arch=${cpu_target_arch:-${host_arch}}
 eessi_os=linux
 job_version=$(cfg_get_value "repository" "repo_version")
-eessi_version=${job_version:-2023.04}
+eessi_version=${job_version:-2023.06}
 job_repo=$(cfg_get_value "repository" "repo_name")
 eessi_repo=${job_repo:-pilot.eessi-hpc.org}
 tar_topdir=/cvmfs/${eessi_repo}/versions
diff --git a/install_compatibility_layer.sh b/install_compatibility_layer.sh
index 84e8edee..b621dccb 100755
--- a/install_compatibility_layer.sh
+++ b/install_compatibility_layer.sh
@@ -10,7 +10,7 @@ REPOSITORY="pilot.eessi-hpc.org"
 RESUME=
 RETAIN_TMP=0
 STORAGE=
-VERSION=2023.04
+VERSION=2023.06
 VERBOSE=
 
 display_help() {