diff --git a/app/assets/templates/shared/_cart.html.erb b/app/assets/templates/shared/_cart.html.erb
index ae12fecf0..76e4918ec 100644
--- a/app/assets/templates/shared/_cart.html.erb
+++ b/app/assets/templates/shared/_cart.html.erb
@@ -5,7 +5,7 @@
 
   <div class="widget-content no-bg auto wrapper" ng-show="events.reserved.length == 0 && (!events.paid || events.paid.length == 0)">
     <p class="font-felt fleche-left text-lg"><%= image_tag('fleche-left.png', class: 'fleche-left visible-lg') %>
-      {{ 'cart.select_one_or_more_slots_in_the_calendar' | translate }}</p>
+      {{ 'cart.select_one_or_more_slots_in_the_calendar' | translate:{SINGLE:limitToOneSlot}:"messageformat" }}</p>
   </div>
 
   <div class="widget-content no-bg auto wrapper" ng-if="events.reserved.length > 0">
diff --git a/config/locales/app.shared.en.yml b/config/locales/app.shared.en.yml
index 097c3100c..73717c478 100644
--- a/config/locales/app.shared.en.yml
+++ b/config/locales/app.shared.en.yml
@@ -409,7 +409,7 @@ en:
         # module de panier d'achat de réservations
         cart:
           summary: "Summary"
-          select_one_or_more_slots_in_the_calendar: "Select one or more slots in the calendar"
+          select_one_or_more_slots_in_the_calendar: "Select one {SINGLE, select, true{slot} other{or more slots}} in the calendar"  # messageFormat interpolation
           you_ve_just_selected_the_slot: "You've just selected the slot:"
           datetime_to_time: "{{START_DATETIME}} to {{END_TIME}}"  # angular interpolation, eg: Thursday, September 4 1986 8:30 PM to 10:00 PM
           cost_of_TYPE: "Cost of {TYPE, select, Machine{a machine hour} Training{the training} other{the element}}"  # messageFormat interpolation
diff --git a/config/locales/app.shared.fr.yml b/config/locales/app.shared.fr.yml
index 7017a24a3..31e080b30 100644
--- a/config/locales/app.shared.fr.yml
+++ b/config/locales/app.shared.fr.yml
@@ -409,7 +409,7 @@ fr:
         # module de panier d'achat de réservations
         cart:
           summary: "Résumé"
-          select_one_or_more_slots_in_the_calendar: "Sélectionnez un ou plusieurs créneaux dans le calendrier"
+          select_one_or_more_slots_in_the_calendar: "Sélectionnez un {SINGLE, select, true{créneau} other{ou plusieurs créneaux}} dans le calendrier"  # messageFormat interpolation
           you_ve_just_selected_the_slot: "Vous venez de sélectionner le créneau :"
           datetime_to_time: "{{START_DATETIME}} à {{END_TIME}}"  # angular interpolation, eg: Thursday, September 4 1986 8:30 PM to 10:00 PM
           cost_of_TYPE: "Coût de {TYPE, select, Machine{l'heure machine} Training{la formation} other{l'élément}}"  # messageFormat interpolation