diff --git a/staffing/views.py b/staffing/views.py
index 9fc1493d..56aaab8e 100644
--- a/staffing/views.py
+++ b/staffing/views.py
@@ -194,8 +194,12 @@ def mission_staffing(request, mission_id):
             return HttpResponseRedirect(reverse("core:forbidden"))
         formset = StaffingFormSet(request.POST, instance=mission)
         if formset.is_valid():
-            saveFormsetAndLog(formset, request)
-            formset = StaffingFormSet(instance=mission)  # Recreate a new form for next update
+            try:
+                saveFormsetAndLog(formset, request)
+                formset = StaffingFormSet(instance=mission)  # Recreate a new form for next update
+            except IntegrityError as e:
+                # Corner case with temporary constraint violation as database does not support deferred constraints
+                formset.management_form.add_error("", _("Duplicate data error"))
     else:
         formset = StaffingFormSet(instance=mission)  # An unbound form
 
@@ -238,8 +242,8 @@ def consultant_staffing(request, consultant_id):
                 saveFormsetAndLog(formset, request)
                 formset = StaffingFormSet(instance=consultant)  # Recreate a new form for next update
             except IntegrityError as e:
-                # Corner case when user update one line that clash with constraint on another line that is removed on the same time
-                formset.management_form.add_error("", e)
+                # Corner case with temporary constraint violation as database does not support deferred constraints
+                formset.management_form.add_error("", _("Duplicate data error"))
     else:
         formset = StaffingFormSet(instance=consultant)  # An unbound form
 
diff --git a/templates/staffing/consultant_staffing.html b/templates/staffing/consultant_staffing.html
index 122c60cf..ee9073a0 100644
--- a/templates/staffing/consultant_staffing.html
+++ b/templates/staffing/consultant_staffing.html
@@ -4,7 +4,7 @@
 
 <div id="pydici-ajax-form-content-consultant-staffing" class="py-2">
     <form action="{% url 'staffing:consultant_staffing' consultant.id %}" method="POST" id="pydici-ajax-form-consultant-staffing">
-        {{ formset.management_form }}
+        <div class="text-danger">{{ formset.management_form }}</div>
         <div class="form-row">
         <table class="table table-striped table-hover table-sm">
            <tr>
diff --git a/templates/staffing/mission_staffing.html b/templates/staffing/mission_staffing.html
index 75c53784..fc28a3a5 100644
--- a/templates/staffing/mission_staffing.html
+++ b/templates/staffing/mission_staffing.html
@@ -15,7 +15,7 @@
     </div>
 
     <form action="{% url 'staffing:mission_staffing' mission.id %}" method="POST" id="pydici-ajax-form-mission-staffing">
-        {{ formset.management_form }}
+        <div class="text-danger">{{ formset.management_form }}</div>
         <div class="form-row">
         <table class="table table-striped table-hover table-sm">
            <tr>