diff --git a/postgres/hooks/postgres_database-relation-joined b/postgres/hooks/postgres_database-relation-joined
index c560fe2..35d61f5 100755
--- a/postgres/hooks/postgres_database-relation-joined
+++ b/postgres/hooks/postgres_database-relation-joined
@@ -45,20 +45,23 @@ else
 fi
 
 
-POSTGIS=$(relation-get postgis 2>/dev/null) || true
-UNACCENT=$(relation-get unaccent 2>/dev/null) || true
-
+array_read-0 extensions < <(relation-get extensions 2>/dev/null | shyaml get-values-0)
 
 ensure_db_docker_running
 
 ## XXXvlab: should send all these into only one docker...
-db_has_database "$DBNAME" || UNACCENT="$UNACCENT" POSTGIS="$POSTGIS" db_create "$DBNAME"
+if ! db_has_database "$DBNAME"; then
+    db_create "$DBNAME" || exit 1
+fi
+if [ "${#extensions[@]}" -gt 0 ]; then
+    db_install_extensions "$DBNAME" "${extensions[@]}" || exit 1
+fi
 if ! db_has_user "$USER"; then
     info "Creating a new user $USER."
-    db_create_user "$USER" "$PASSWORD"
+    db_create_user "$USER" "$PASSWORD" || exit 1
 else
     info "Updating password of user $USER."
-    db_change_password "$USER" "$PASSWORD"
+    db_change_password "$USER" "$PASSWORD" || exit 1
 fi
 
 db_grant_rights "$DBNAME" "$USER"
diff --git a/postgres/lib/common b/postgres/lib/common
index d78c259..34e351b 100644
--- a/postgres/lib/common
+++ b/postgres/lib/common
@@ -44,17 +44,26 @@ db_create () {
     local dbname="$1"
     dcmd createdb "$dbname" || return 1
     info "Database '$dbname' created."
-    if [ "$POSTGIS" ]; then
-        ddb -d "$dbname" < <(echo "CREATE EXTENSION postgis; CREATE EXTENSION postgis_topology;") || return 1
-        dcmd /bin/bash -c "psql -d '$dbname' -f /usr/share/postgresql/*/contrib/postgis-2.1/legacy.sql" || return 1
-        info "Installed postgis extensions on database '$dbname'."
-    fi
-    if [ "$UNACCENT" ]; then
-        ddb -d "$dbname" < <(echo "CREATE EXTENSION IF NOT EXISTS unaccent;") || return 1
-        info "Installed unaccent extension on database '$dbname'."
-    fi
 }
 
+db_install_extensions() {
+    local dbname="$1"
+    shift
+    while [ "$#" != 0 ]; do
+        case "$1" in
+            postgis)
+                ddb -d "$dbname" < <(echo "CREATE EXTENSION postgis; CREATE EXTENSION postgis_topology;") || return 1
+                dcmd /bin/bash -c "psql -d '$dbname' -f /usr/share/postgresql/*/contrib/postgis-2.1/legacy.sql" || return 1
+                info "Installed postgis extensions on database '$dbname'."
+                ;;
+            *)
+                ddb -d "$dbname" < <(echo "CREATE EXTENSION IF NOT EXISTS $1;") || return 1
+                info "Installed $1 extension on database '$dbname'."
+                ;;
+        esac
+        shift
+    done
+}
 
 ## XXXvlab: if launched first, it'll fail handling correctly the open/close of docker
 db_has_database() {