diff --git a/app/validators/mon_avis_embed_validator.rb b/app/validators/mon_avis_embed_validator.rb
index b4fb33f59..3fb87b456 100644
--- a/app/validators/mon_avis_embed_validator.rb
+++ b/app/validators/mon_avis_embed_validator.rb
@@ -1,9 +1,31 @@
+# We need to ensure the embed code is not any random string in order to avoid injections
 class MonAvisEmbedValidator < ActiveModel::Validator
+  class MonAvisEmbedError < StandardError; end
+  # from time to time, they decide to change domain just for fun. if it breaks, check the new subdomain
+  KNOWN_SUBDOMAIN = ['jedonnemonavis', 'monavis', 'voxusagers']
+  HREF_CHECKER = /https:\/\/#{KNOWN_SUBDOMAIN.join('|')}.numerique.gouv.fr\/Demarches\/\d+.*key=[[:alnum:]]+.*/
+  IMG_CHECKER = /https:\/\/#{KNOWN_SUBDOMAIN.join('|')}.numerique.gouv.fr\/(monavis-)?static\/bouton-blanc|bleu.png|svg/
+
   def validate(record)
-    # We need to ensure the embed code is not any random string in order to avoid injections
-    r = Regexp.new('<a href="https://monavis|voxusagers.numerique.gouv.fr/Demarches/\d+.*key=[[:alnum:]]+.*">\s*<img src="https://monavis|voxusagers.numerique.gouv.fr/(monavis-)?static/bouton-blanc|bleu.png|svg" alt="Je donne mon avis" (title="Je donne mon avis sur cette démarche" )?/>\s*</a>', Regexp::MULTILINE)
-    if record.monavis_embed.present? && !r.match?(record.monavis_embed)
-      record.errors.add :base, :invalid, message: "Le code fourni ne correspond pas au format des codes MonAvis reconnus par la plateforme."
+    if record.monavis_embed.present?
+      embed = Nokogiri::HTML(record.monavis_embed)
+      check_link(embed.css('a'))
+      check_img(embed.css('img'))
     end
+  rescue MonAvisEmbedError => e
+    record.errors.add :base, :invalid, message: "Le code fourni ne correspond pas au format des codes MonAvis reconnus par la plateforme. #{e.message}"
+  rescue # nokogiri
+    record.errors.add :base, :invalid, message: "Le code fourni ne correspond pas au format des codes MonAvis reconnus par la plateforme."
+  end
+
+  def check_link(links)
+    raise MonAvisEmbedError.new("le code monavis doit comporter un seul lien") if links.size != 1
+    raise MonAvisEmbedError.new("le lien du bouton mon avis doit pointer vers le bon domaine") if !HREF_CHECKER.match?(links.first['href'])
+  end
+
+  def check_img(imgs)
+    raise MonAvisEmbedError.new("le code monavis doit comporter une seule image") if imgs.size != 1
+    raise MonAvisEmbedError.new("l'image du bouton mon avis ne pointe pas vers le bon domaine") if !IMG_CHECKER.match?(imgs.first['src'])
+    raise MonAvisEmbedError.new("l'image du bouton mon avis n'a pas d'attribut alt") if imgs.first['alt'].blank?
   end
 end
diff --git a/lib/tasks/deployment/20240220104123_disable_invalid_monavis.rake b/lib/tasks/deployment/20240220104123_disable_invalid_monavis.rake
new file mode 100644
index 000000000..9e587f58c
--- /dev/null
+++ b/lib/tasks/deployment/20240220104123_disable_invalid_monavis.rake
@@ -0,0 +1,23 @@
+namespace :after_party do
+  desc 'Deployment task: disable_invalid_monavis'
+  task disable_invalid_monavis: :environment do
+    puts "Running deploy task 'disable_invalid_monavis'"
+    # rubocop:disable DS/Unscoped
+    all_procedures = Procedure.unscoped.where.not(monavis_embed: nil)
+    # rubocop:enable DS/Unscoped
+    progress = ProgressReport.new(all_procedures.count)
+
+    all_procedures.find_each do |procedure|
+      if !procedure.valid? && procedure.errors.key?(:monavis_embed)
+        procedure.update_column(:monavis_embed, '')
+        rake_puts "fix: #{procedure.id}"
+      end
+      progress.inc(1)
+    end
+    progress.finish
+    # Update task as completed.  If you remove the line below, the task will
+    # run with every deploy (or every time you call after_party:run).
+    AfterParty::TaskRecord
+      .create version: AfterParty::TaskRecorder.new(__FILE__).timestamp
+  end
+end
diff --git a/spec/models/procedure_spec.rb b/spec/models/procedure_spec.rb
index e6361eaa9..9a7899c8d 100644
--- a/spec/models/procedure_spec.rb
+++ b/spec/models/procedure_spec.rb
@@ -294,6 +294,26 @@ describe Procedure do
         let(:procedure) { build(:procedure, monavis_embed: monavis_issue_bouchra) }
         it { expect(procedure.valid?).to eq(true) }
       end
+
+      context 'Monavis embed code with jedonnemonavis' do
+        monavis_jedonnemonavis = <<-MSG
+          <a href="https://jedonnemonavis.numerique.gouv.fr/Demarches/3839?&view-mode=formulaire-avis&nd_source=button&key=6af80846f64fb213abcabaeea7a3ea8c">
+            <img src="https://jedonnemonavis.numerique.gouv.fr/static/bouton-bleu.svg" alt="Je donne mon avis" />
+          </a>
+        MSG
+        let(:procedure) { build(:procedure, monavis_embed: monavis_jedonnemonavis) }
+        it { expect(procedure.valid?).to eq(true) }
+      end
+
+      context 'Monavis embed code with kthxbye' do
+        monavis_jedonnemonavis = <<-MSG
+          <a href="https://kthxbye.fr/?key=6af80846f64fb213abcabaeea7a3ea8c">
+            <img src="https://kthxbye.fr/static/bouton-bleu.svg" alt="Je donne mon avis" />
+          </a>
+        MSG
+        let(:procedure) { build(:procedure, monavis_embed: monavis_jedonnemonavis) }
+        it { expect(procedure.valid?).to eq(false) }
+      end
     end
 
     describe 'duree de conservation dans ds' do