diff --git a/data/hooks/conf_regen/12-metronome b/data/hooks/conf_regen/12-metronome
index 5a50b2b6e..8aee90212 100755
--- a/data/hooks/conf_regen/12-metronome
+++ b/data/hooks/conf_regen/12-metronome
@@ -14,7 +14,6 @@ do_pre_regen() {
 
   # retrieve variables
   main_domain=$(cat /etc/yunohost/current_host)
-  domain_list=$(yunohost domain list --output-as plain --quiet)
 
   # install main conf file
   cat metronome.cfg.lua \
@@ -22,7 +21,7 @@ do_pre_regen() {
     > "${metronome_dir}/metronome.cfg.lua"
 
   # add domain conf files
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     cat domain.tpl.cfg.lua \
       | sed "s/{{ domain }}/${domain}/g" \
       > "${metronome_conf_dir}/${domain}.cfg.lua"
@@ -33,7 +32,7 @@ do_pre_regen() {
                  | awk '/^[^\.]+\.[^\.]+.*\.cfg\.lua$/ { print $1 }')
   for file in $conf_files; do
     domain=${file%.cfg.lua}
-    [[ $domain_list =~ $domain ]] \
+    [[ $YNH_DOMAINS =~ $domain ]] \
       || touch "${metronome_conf_dir}/${file}"
   done
 }
@@ -43,10 +42,9 @@ do_post_regen() {
 
   # retrieve variables
   main_domain=$(cat /etc/yunohost/current_host)
-  domain_list=$(yunohost domain list --output-as plain --quiet)
 
   # create metronome directories for domains
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     mkdir -p "/var/lib/metronome/${domain//./%2e}/pep"
   done
   # http_upload directory must be writable by metronome and readable by nginx
diff --git a/data/hooks/conf_regen/15-nginx b/data/hooks/conf_regen/15-nginx
index f1a278440..a43107599 100755
--- a/data/hooks/conf_regen/15-nginx
+++ b/data/hooks/conf_regen/15-nginx
@@ -46,7 +46,6 @@ do_pre_regen() {
 
   # retrieve variables
   main_domain=$(cat /etc/yunohost/current_host)
-  domain_list=$(yunohost domain list --output-as plain --quiet)
 
   # Support different strategy for security configurations
   export compatibility="$(yunohost settings get 'security.nginx.compatibility')"
@@ -55,7 +54,7 @@ do_pre_regen() {
   cert_status=$(yunohost domain cert-status --json)
 
   # add domain conf files
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     domain_conf_dir="${nginx_conf_dir}/${domain}.d"
     mkdir -p "$domain_conf_dir"
     mail_autoconfig_dir="${pending_dir}/var/www/.well-known/${domain}/autoconfig/mail/"
@@ -83,7 +82,7 @@ do_pre_regen() {
                  | awk '/^[^\.]+\.[^\.]+.*\.conf$/ { print $1 }')
   for file in $conf_files; do
     domain=${file%.conf}
-    [[ $domain_list =~ $domain ]] \
+    [[ $YNH_DOMAINS =~ $domain ]] \
       || touch "${nginx_conf_dir}/${file}"
   done
 
@@ -91,7 +90,7 @@ do_pre_regen() {
   autoconfig_files=$(ls -1 /var/www/.well-known/*/autoconfig/mail/config-v1.1.xml 2>/dev/null || true)
   for file in $autoconfig_files; do
     domain=$(basename $(readlink -f $(dirname $file)/../..))
-    [[ $domain_list =~ $domain ]] \
+    [[ $YNH_DOMAINS =~ $domain ]] \
       || (mkdir -p "$(dirname ${pending_dir}/${file})" && touch "${pending_dir}/${file}")
   done
 
@@ -105,16 +104,13 @@ do_post_regen() {
 
   [ -z "$regen_conf_files" ] && exit 0
 
-  # retrieve variables
-  domain_list=$(yunohost domain list --output-as plain --quiet)
-
   # create NGINX conf directories for domains
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     mkdir -p "/etc/nginx/conf.d/${domain}.d"
   done
 
   # Get rid of legacy lets encrypt snippets
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
       # If the legacy letsencrypt / acme-challenge domain-specific snippet is still there
       if [ -e /etc/nginx/conf.d/${domain}.d/000-acmechallenge.conf ]
       then
diff --git a/data/hooks/conf_regen/19-postfix b/data/hooks/conf_regen/19-postfix
index 10076b680..68afe4bc9 100755
--- a/data/hooks/conf_regen/19-postfix
+++ b/data/hooks/conf_regen/19-postfix
@@ -20,18 +20,17 @@ do_pre_regen() {
 
   # prepare main.cf conf file
   main_domain=$(cat /etc/yunohost/current_host)
-  domain_list=$(yunohost domain list --output-as plain --quiet | tr '\n' ' ')
 
   # Support different strategy for security configurations
   export compatibility="$(yunohost settings get 'security.postfix.compatibility')"
 
   export main_domain
-  export domain_list
+  export domain_list="$YNH_DOMAINS"
   ynh_render_template "main.cf" "${postfix_dir}/main.cf"
 
   cat postsrsd \
     | sed "s/{{ main_domain }}/${main_domain}/g" \
-    | sed "s/{{ domain_list }}/${domain_list}/g" \
+    | sed "s/{{ domain_list }}/${YNH_DOMAINS}/g" \
     > "${default_dir}/postsrsd"
 
   # adapt it for IPv4-only hosts
diff --git a/data/hooks/conf_regen/31-rspamd b/data/hooks/conf_regen/31-rspamd
index 26fea4336..861549e27 100755
--- a/data/hooks/conf_regen/31-rspamd
+++ b/data/hooks/conf_regen/31-rspamd
@@ -25,11 +25,8 @@ do_post_regen() {
   mkdir -p /etc/dkim
   chown _rspamd /etc/dkim
 
-  # retrieve domain list
-  domain_list=$(yunohost domain list --output-as plain --quiet)
-
   # create DKIM key for domains
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     domain_key="/etc/dkim/${domain}.mail.key"
     [ ! -f "$domain_key" ] && {
       # We use a 1024 bit size because nsupdate doesn't seem to be able to
diff --git a/data/hooks/conf_regen/43-dnsmasq b/data/hooks/conf_regen/43-dnsmasq
index 59a1f8a06..8a2985f34 100755
--- a/data/hooks/conf_regen/43-dnsmasq
+++ b/data/hooks/conf_regen/43-dnsmasq
@@ -26,10 +26,9 @@ do_pre_regen() {
   ynh_validate_ip4 "$ipv4" || ipv4='127.0.0.1'
   ipv6=$(curl -s -6 https://ip6.yunohost.org 2>/dev/null || true)
   ynh_validate_ip6 "$ipv6" || ipv6=''
-  domain_list=$(yunohost domain list --output-as plain --quiet)
 
   # add domain conf files
-  for domain in $domain_list; do
+  for domain in $YNH_DOMAINS; do
     cat domain.tpl \
       | sed "s/{{ domain }}/${domain}/g" \
       | sed "s/{{ ip }}/${ipv4}/g" \
@@ -42,7 +41,7 @@ do_pre_regen() {
   conf_files=$(ls -1 /etc/dnsmasq.d \
                  | awk '/^[^\.]+\.[^\.]+.*$/ { print $1 }')
   for domain in $conf_files; do
-    [[ $domain_list =~ $domain ]] \
+    [[ $YNH_DOMAINS =~ $domain ]] \
       || touch "${dnsmasq_dir}/${domain}"
   done
 }
diff --git a/src/yunohost/regenconf.py b/src/yunohost/regenconf.py
index ad84c8164..b81c043ce 100644
--- a/src/yunohost/regenconf.py
+++ b/src/yunohost/regenconf.py
@@ -141,7 +141,14 @@ def regen_conf(operation_logger, names=[], with_diff=False, force=False, dry_run
     if "glances" in names:
         names.remove("glances")
 
-    pre_result = hook_callback('conf_regen', names, pre_callback=_pre_call)
+    # [Optimization] We compute and feed the domain list to the conf regen
+    # hooks to avoid having to call "yunohost domain list" so many times which
+    # ends up in wasted time (about 3~5 seconds per call on a RPi2)
+    from yunohost.domain import domain_list
+    env = {}
+    env["YNH_DOMAINS"] = " ".join(domain_list()["domains"])
+
+    pre_result = hook_callback('conf_regen', names, pre_callback=_pre_call, env=env)
 
     # Keep only the hook names with at least one success
     names = [hook for hook, infos in pre_result.items()
@@ -310,7 +317,7 @@ def regen_conf(operation_logger, names=[], with_diff=False, force=False, dry_run
             regen_conf_files = ''
         return post_args + [regen_conf_files, ]
 
-    hook_callback('conf_regen', names, pre_callback=_pre_call)
+    hook_callback('conf_regen', names, pre_callback=_pre_call, env=env)
 
     operation_logger.success()