diff --git a/hooks/conf_regen/12-metronome b/hooks/conf_regen/12-metronome
index e0797e673..220d18d58 100755
--- a/hooks/conf_regen/12-metronome
+++ b/hooks/conf_regen/12-metronome
@@ -49,12 +49,8 @@ do_post_regen() {
     # retrieve variables
     main_domain=$(cat /etc/yunohost/current_host)
 
-    # FIXME : small optimization to do to avoid calling a yunohost command ...
-    # maybe another env variable like YNH_MAIN_DOMAINS idk
-    domain_list=$(yunohost domain list --exclude-subdomains --output-as plain --quiet)
-
     # create metronome directories for domains
-    for domain in $domain_list; do
+    for domain in $YNH_MAIN_DOMAINS; do
         mkdir -p "/var/lib/metronome/${domain//./%2e}/pep"
         # http_upload directory must be writable by metronome and readable by nginx
         mkdir -p "/var/xmpp-upload/${domain}/upload"
diff --git a/src/regenconf.py b/src/regenconf.py
index 5922e6832..c763fb6b6 100644
--- a/src/regenconf.py
+++ b/src/regenconf.py
@@ -140,6 +140,7 @@ def regen_conf(
     # though kinda tight-coupled to the postinstall logic :s
     if os.path.exists("/etc/yunohost/installed"):
         env["YNH_DOMAINS"] = " ".join(domain_list()["domains"])
+        env["YNH_MAIN_DOMAINS"] = " ".join(domain_list(exclude_subdomains=True)["domains"])
 
     pre_result = hook_callback("conf_regen", names, pre_callback=_pre_call, env=env)